International Journal of Industrial and Systems Engineering (129 papers in press)
Reliability-based measures for a batch-arrival queue with an un-reliable server and delayed repair under randomized vacations
by Jau-Chuan Ke, Kai-Bin Huang, Ching-Chang Kuo
Abstract: This paper studies the transient and the steady-state behavior of an M[x]/G/1 queueing system with a randomized vacation policy and at most J vacations. Whenever the system is empty, the server immediately takes a vacation. If no customers are waiting for service at the end of a vacation, the server either remains idle with probability p or leaves for another vacation with probability 1-p. This pattern continues until the number of vacations taken reaches J. Assume that the server may meet an unpredictable breakdown according to a Poisson process and the repair may be delayed, in which the repair time is a general random variable. Based on the supplementary variable technique, we developed the transient and the steady-state solutions for both queueing and reliability measures of the variant vacation system.
Keywords: Delayed repair; MTTF; Randomized vacation; Reliability; Supplementary variable technique
A novel method for ranking fuzzy quantities using center of incircle and its application to a petroleum distribution center evaluation problem
by Seyed Hadi Nasseri, Ali Ebrahimnejad, Nemat Taghi-Nezhad
Abstract: Ranking fuzzy numbers is an important issue in decision making analysis, optimization, artificial intelligence and operations research. Therefore, many methods have been proposed for ranking fuzzy numbers in the literature. However all of these methods have some limitations and shortcomings. Thus in this paper, based on coordinates of the center of in-circle of triangles a novel ranking method is proposed to overcome the existing shortcomings. Since the in-circle of each triangle is defined as unique, the coordinates of the in-circle center are used in the proposed ranking approach. The novel ranking method is proven to always guarantee consistency between the ranking of fuzzy quantities and that of their images. Unlike many existing methods, the proposed method not only can rank real numbers as well as normal and non-normal fuzzy numbers, but it also has some other noticeable mathematical properties that are proved in this paper. Moreover, several comparative examples are examined to show the superior validity, applicability, efficiency and simplicity of the proposed method in comparison with the existing methods. Finally a petroleum distribution center evaluation problem is given as a practical application to demonstrate the usage and applicability of the proposed ranking approach.
Keywords: Fuzzy quantity; Ranking; Centroid points; Incenter; Petroleum distribution center evaluation problem.
Pedagogical Research on Understanding and Misconceptions of System Design
by Rashmi Jain, Anithashree Chandrasekaran, George Elias
Abstract: Systems engineering is a life cycle approach to engineering design: the integration of numerous technical and non-technical disciplines in the development of new products, systems and services (Sage, 1992). While there is clear evidence of the expansion of SE as a field of engineering, there is surprisingly little research on core concepts and common misconceptions particular to the field. A recent review of literature found no systematic studies of engineering students conceptual understanding of fundamental engineering conceptsincluding those pertaining to SEdespite much research on important concepts in the sciences (Streveler, 2004).
This paper is based on authors research to identify and define the foundational concepts of system design. This paper proposes five key concepts of systems engineering, namely, context, interdisciplinarity, value, trade-offs, and abstraction (Jain R. Chandrasekaran A., 2008). The understanding of these concepts were tested on students to identify their misconceptions based on intuitively formed understandings and misinformation learned elsewhere.
Keywords: Concept Inventory, system design, design context, interdisciplinarity, value, trade-offs, abstraction, pedagogy
Introduction of Scope Creep Life Cycle for Effective Scope Creep Management in Software Industries
by Lakshmi Madhuri, Suma V
Abstract: Advancement in technology has led software to be one of significantly required component of every industry. Therefore, total customer satisfaction in industry can be achieved only through developing high quality software. Hence, various best practices and strategies are followed to ensure the above-said objective. Nevertheless, it is yet not possible to develop completely customer satisfied software products. This is because it is well proven that several parameters influence the total project success. Scope creep is one such major parameter for the software project success. Aim of this paper is therefore to comprehend the implications of scope creep on total project success and also upon various other parameters. This research involves case study carried out in a sampled software industry where projects from domains such as telecom and retail are investigated. From the investigation, various inferences and observations are drawn which has led towards the introduction of Scope Creep Life Cycle (SCLC). Implementation of this enhanced mode of managing scope creep through integration of scope creep life cycle in software development process ensures retention of quality and project success leading towards assured total customer satisfaction.
Keywords: Software Engineering, Software Quality, Scope Creep Management, Total Customer Satisfaction, Software Process
Life Cycle Assessment of an Aircraft Component: A Case Study
by Veeramanikandan R, Nithish S, Sivaraj G, S. Vinodh
Abstract: Increasing awareness on environmental protection is being noticed by aviation industries to develop aircraft with light weight and minimal environmental impact. For this purpose Environmental Impact (EI) of aircraft to be determined. This article presents Life Cycle Assessment (LCA) of turbine blade used in aircraft engine system. LCA can provide detailed information about chosen material or component from its manufacturing to disposal phase. Environmental Impact (EI) of various entities is being analyzed using LCA package. LCA has mainly focused on the environmental impact of the life cycle phases of components. The assessment results showed that plating has highest impact followed by raw material. The conduct of study enables the determination of environmental impacts over the life cycle of the aircraft components.
Keywords: Life Cycle Assessment; Turbine Blades; Machining Process; Environmental Impact.
Prioritizing Factors for Manufacturing Growth in India: An Analytic Network Process Approach
by Ravindra Ojha, Prem Vrat
Abstract: The purpose of the paper has been to analyse the role, the impact and setting up right priorities of the thirteen growth factors involved in accelerating Indias manufacturing sector growth. An Analytic Network Process (ANP) framework has been developed with a goal of accelerating Indian manufacturing growth which is influenced by eight key-drivers and five manufacturing industry-segments. In order to find the comparative weights of the factors a questionnaire-based survey was carried out on 42 experts from the top-management of industry, consultancy and academia. In the current low manufacturing growth rate environment, the Indian manufacturing industry segments needing high priority are: Resource-intensive, Global technology & Innovation and Global innovation for local-market. The vital-few five key-drivers for fast-tracking manufacturing growth are: Good-Governance, Technology-deployment, Core-infrastructure, Investment & Financing and Worker-skill. The application of ANP approach has provided some useful insights to the policy-makers on setting the priorities for the Indian manufacturing strategy.
Keywords: Manufacturing growth factors; Key drivers; Manufacturing segments; ANP and Priorities.
Solving stochastic dynamic facility layout problems using proposed hybrid AC-CS-SA meta-heuristic algorithm
by Ghorbanali Moslemipour, Tian Lee, Y. Loong
Abstract: This paper proposes a novel hybrid algorithm in which simulated annealing algorithm starts with a population of good initial solutions constructed by combining ant colony, clonal selection, and robust layout design approaches. The proposed algorithm can be used to solve a dynamic (multi-period) facility layout problem in both deterministic and stochastic cases. In the stochastic environment, product demands are assumed to be normally distributed random variables with known probability density function that changes from period to period at random. In addition, a quadratic assignment-based mathematical model, which is used in the proposed hybrid algorithm, is developed to design a robust layout for the stochastic dynamic layout problem. Finally, the performance of the proposed algorithm is evaluated by solving a large number of randomly generated test problems and some test problems from the literature in stochastic and deterministic cases respectively. The results show that the hybrid algorithm has an outstanding performance from both solution quality and computational time points of view.
Keywords: Ant colony optimization; Clonal selection; Simulated annealing; Stochastic dynamic layout problem;.
An integrated approach for fuzzy reliability analysis and resource allocation of a repairable industrial system
Abstract: In this paper, an integrated approach for fuzzy reliability analysis and resource allocation has been presented for a paper machine of a paper mill comprises forming, press and dryer units. In the presented approach, imprecise and vague failure/repair data of system components is fuzzified using triangular fuzzy numbers(TFNs). Using fuzzified data, genetic algorithms based lambda-tau(GABLT) technique is used to obtain system main subsystems(stages) fuzzy reliabilities which are then defuzzified. A resource allocation problem(RAP) has been formulated as a multistage decision-making problem. Formulated RAP considers system reliability as the objective function while maintenance and manpower costs as constraints. The approach makes use of defuzzified values of subsystems reliability along with relevant system information (number of components, manpower, cost ranges). Resulting single objective optimization problem is then solved by using dynamic programming based on recursive Lagrange multiplier technique. To show the merits of the approach, computed results have been compared with existing results.
Keywords: System reliability; Triangular fuzzy number; Resource allocation problem; GABLT; Lagrange multiplier technique.
Developing Heuristic algorithms for Optimization of Location-allocation of Fuel-distribution Network
by Jafar Bagherinejad, Maryam Mirzaei
Abstract: The subject of this paper is to determine the optimal locations for the construction of refueling stations for vehicles in urban distribution networks including paths and intersections. The aim is to maximize the covered demand with certain number of facilities. For this purpose, mathematical modeling of location-allocation based on the maximum coverage, is developed. Considering the service capacity constraint for refueling stations is one of the innovations of this research. Changing the approach from the node-based to path-based for demands and facility location makes a new way to the location problems of this field. In this research three heuristic algorithms have been developed for three states including; state 1: demand and facility location are node-based; state 2: path-based demand and node-based facility location; state 3: demand and facility location are both path-based. The impact of service capacity constraint has been analyzed in all these three states. The obtained results show that taking into account the service capacity constraint, avoids congestion around the refueling stations that can reduce the roads risks, wasting time and the related cost. The path-based oriented approach in a network includes demands and the related on paths which makes the solution space and final solution to be more real. The proposed algorithms were approved by solving a numerical example. The overall findings show that in the maximal covering of demands the third heuristic algorithm is better than others based on the lower number of determined stations.
Keywords: refueling location model; heuristic algorithm; maximal covering; path-based approach; service capacity constraint
Analysis of A Standby Redundant System with Controlled Arrival of Failed Machines
by Fu-Min Chang, Yu-Tang Lee, Chia-Jung Chang, Chung Yeh
Abstract: Systems reliability and availability are an important issue in power plants, manufacturing systems, and industrial systems. This study investigates the issues of reliability and availability in the machine repair system. A controlling arrival policy is employed to maintain the repair quality of maintenance facility. The operation of control policy is when the number of failed machines reaches the maintenance facilitys capacity, no further arriving failed machines are allowed to enter the maintenance facility until the maintenance facility capacity decreases to a certain threshold value F. For such system, we derive the explicit expressions for the steady-state availability, the steady-state busy period, and the mean time to system failure. We also perform a parametric analysis for investigating the effect of changes in the system parameters on the total expected profit function and the cost effectiveness function. Several cases are analyzed graphically to study the effect of various parameters on the reliability and mean time to failure (MTTF) of the system.
Keywords: Controlling arrival policy, Steady-state availability, Busy period, Mean time to failure.
The training of suppliers: a linear model for optimizing the allocation of available hours
by Francesco Lolli, Rita Gamberini, Mauro Gamberi, Marco Bortolini
Abstract: The cost of quality represents a relevant item in total manufacturing costs. The learning process is incorporated into contemporary models because of its impact on unitary production costs through both autonomous (learning by doing) and induced (learning by means of proactive actions) learning processes. A learning model with time-varying learning rate is proposed in order to establish the relationship between quality improvements and training hours to allocate to suppliers. The performance indicator adopted is the rate of non-conforming units, rather than the more traditional process variance. This enables definition of a novel total cost function, which can be minimised for the best allocation of training hours to suppliers during a single learning cycle. A novel criterion also emerges for the evaluation of suppliers in terms of investment opportunity. Finally, a case study was carried out in order to verify the applicability of this model to real industrial settings.
Keywords: learning curves; cost of quality; continuous improvement; non-conforming units
Application of intuitionistic fuzzy numbers in SWOT analysis
by Emad Roghanian, Baharak Ghorbani, Mohammad Alipour
Abstract: Strategic studies are of high importance in every business administration. Some of them, like Strengths, Weaknesses, Opportunities, Threats (SWOT), can be used widely. However uncertainty is always considered as a major obstacle for extracting strategies from these techniques. On the other hand, introduction of fuzzy logic facilitates the connection between real world managerial problems and deterministic mathematics. This paper focused on vague characteristic of the data used in SWOT analysis, and tried to solve it by utilization of the Intuitionistic Fuzzy Numbers (IFN), as a transformation which enables the outcome of this procedure to be identified more explicitly.
Keywords: SWOT; Fuzzy set; Intuitionistic Fuzzy Number; α-cut.
GA Based Optimization using RSM in WEDM of Nimonic-90: A Nickel Based Super Alloy
by Vinod Kumar, Kamal Kumar, Vikas Kumar, Neeraj Sharma
Abstract: The present research work is focused on optimization of WEDM process parameters for machining of Nimonic-90. It is a nickel based alloy possessing creep resistance and high rupture strength at high temperature (up to 950 oC). Genetic algorithm (GA) and response surface methodology (RSM) incorporated with each other to optimize the process parameters. Four input process parameters viz. discharge current (Ip), pulse-off time (Toff), pulse-on time (Ton), and servo voltage (SV) have been investigated and modelled for surface roughness (SR) utilizing RSM. In present experimentation, quadratic model has been suggested for surface roughness. Pulse-on time is most significant effect on surface roughness as compared to other parameters. Finally, genetic algorithm, a popular evolutionary approach is used to optimize the process parameters. Using SEM micrographs and micro-hardness profile, effect of discharge energy on surface morphology has been examined.
Keywords: WEDM; Nimonic-90; Response surface methodology (RSM); Surface Roughness; Genetic algorithm (GA).
Analysis of Damage Costs in Supply Chain Systems
by Samir Alsobhi, Krishna K. Krishnan, Deepak Gupta, Abdulaziz Almaktoom
Abstract: In a supply chain system, products get damaged during shipping due to transportations hazards and poor packaging. The most common hazards in transportation include shocks, vibrations, accident, handling, etc. Damage from accidents and handling issues are not completely within the control of packaging. However, proper packaging can prevent most of the damage from shocks and vibration. The loss due to damage at each stage of the supply chain network can be reduced by selecting the appropriate packaging, transportation method and by shipping under assembled or unassembled condition. There is not much literature available in the area of goods damaged during shipping as applied to supply chain systems. A mathematical model which minimizes the total costs (damage costs, shipping costs, and packaging costs) has been developed to address the issue of damage costs. The model is implemented in MATLAB. The mathematical models were verified by using total enumeration strategy. Case studies to illustrate and validate the procedure were developed and implemented in MATLAB.
Keywords: damage cost; supply chain risk; shortest path; shipping cost; packaging cost
Finite difference solution to stochastic partial differential equations in reliability
by Arpan Gupta, Mangey Ram
Abstract: The paper presents a numerical method to solve for the reliability measures of a Markovian system. The model is obtained from the field of reliability engineering for systems having constant failure and repair rates. Generally, the steady state behavior of the system is studied due to some constraint on obtaining the transition state solution. The proposed method helps to govern the transition state probability values, by utilizing a finite difference method in concurrence with the results of integral appearing in stochastic differential equation obtained using the supplementary variable technique. Results, thus achieved are found to be effective for studying the transition state behaviour of the system.
Keywords: Reliability modeling; stochastic process; finite difference method; transition state probabilities.
Kinematical Performance Prediction Method for Rotary Axes of 5-Axis Machine Tool in Processing of Complex Curved Surface
by Jiyun Qin, Zhenyuan Jia, Jianwei Ma, Dening Song, Likun Si
Abstract: The 5-axis machine tool has obvious advantages in processing parts with complex curved surface. Due to the shape complexity of the curved surface and the inflexibility programming of tool orientation, the velocity, acceleration and jerk of rotary axes of 5-axis machine tool always fluctuate significantly during 5-axis High Speed Machining (HSM), which is one of the important reasons for affecting the quality and the efficiency in 5-axis machining. In this study, a kinematical performance prediction method for rotary axes of 5-axis machine tool is presented, and the velocity, acceleration and jerk of rotary axes during the actual machining can be pre-calculated by it. The prediction method can be easily integrated into the self-made CAM system and can constitute as an indicator for 5-axis trajectory optimization and feed scheduling. To verify the proposed method, two tests are conducted on a 5-axis milling machine tool controlled by SINUMERIK 840D system, and the prediction results are perfectly matched with the measured results got by 840D system.
Keywords: 5-Axis machine tool; Complex curved surface machining; Rotary axes; Kinematical performance prediction
A Flexible Clustering Approach for Virtual Cell Formation considering Real-life Production Factors using Kohonen Self-organizing Map
by Siba Sankar Mahapatra, D.P. Tambuskar, B.E. Narkhede
Abstract: In dynamic production environment, quick adaptation for new product design is an important issue to achieve competitive edge. To address this issue, virtual cellular manufacturing has been evolved to improve shop flexibility and setup efficiency of cellular manufacturing system. The virtual manufacturing cell (VMC) involves grouping of parts to form part families and grouping of machines to form machine cells without physical boundaries of cells. Kohonens self-organizing map (KSOM), an unsupervised neural network technique, is employed in this work for cell formation because of its flexibility in dynamic clustering of parts and machines. The proposed KSOM network approach considers real life production factors like processing time, operation sequence, routing flexibility, machine capacity, machine flexibility and demand to design machine cells. A numerical example from literature is used to illustrate the proposed methodology. The methodology is tested on benchmark problems of different size and performance measures such as group technology efficiency (GTE) and exceptional elements (EE) are evaluated. The results indicate that the proposed approach is quite capable of solving different sizes of problems and outperforms the existing methods in some cases.
Keywords: Virtual manufacturing cell (VMC); Kohonen self-organizing map (KSOM); Group technology efficiency; Exceptional element
The Linkages between Horizontal Strategy, Person-Environment fit and Horizontal Fit: An Empirical study
by Pratima Verma, R.R.K. Sharma
Abstract: The main purpose of this paper is to identify the relationship between horizontal strategy, person-environment fit and horizontal fit. The selection of employees in the organization, based on their skills, capabilities and knowledge, so organization recruitment strategy or functions should associated to corporate or organization strategy. Horizontal strategy is corporate strategy which is very difficult to execute in the real world because there is no generalized and standardized methods. Todays the best companies are horizontally integrated for achievement of sustainable competitive advantage that cannot easily imitated. Consequently, we are trying to determine the types of employee selection (person-environment fit) are associated to horizontal strategy. In addition, this study is also determining the influence of all dimensions of person-environment fit on horizontal alignment and horizontal strategy.
Based on literature, seven hypotheses are posed on how all the dimensions of person-environment fit affects horizontal fit and horizontal strategy. The study uses a structured questionnaire which was developed using extant literature. The empirical data was drawn from 267 organizations in India. The data was analyzed using correlation and multiple regression analyses to validate these hypotheses. The multiple regression output illustrate that person-group fit is most significant and positive impact on horizontal strategy; and negative relationship between person job fit and horizontal strategy. Our present study is unique in terms of scope and its contribution to the theory and practice of horizontal strategy.
Keywords: Horizontal strategy, Horizontal fit, person-environment fit, person-job fit, person-organization fit, and person-group fit
Effect of moisture in gasification of biomass using entrained flow gasifier at constant equivalence ratio
by Dillip Mohanty, Abhijit Padhiary
Abstract: Biomass entrained flow gasification is a promising technology due to its commercial availability, high efficiency and high potential for the production of biofuels and chemicals from biomass. The entrained flow gasification has been investigated in order to evaluate the effect of the moisture content at a fixed equivalence ratio on the gasifier performance and the producer gas quality. The composition of the producer gas and the adiabatic flame temperature has been analyzed with moisture varying from 10 to 30% at an equivalence ratio of 0.2609. The results show that steam gasification gives more yield of fuel while the temperature reduces with moisture content. The Optimum moisture content to maximize the fuel content maintaining the reaction temperature at 1000 K is found to be 18-19 %. Simultaneously the optimum calorific value of the fuel is found to be 7- 8 MJ/Nm3.
Keywords: Biomass; entrained flow gasifier; equivalence ratio; moisture; adiabatic flame temperature.
Reliability analysis of non-repairable weighted k-out-of-n system using belief universal generating function
by Namita Jaiswal, Seema Negi, S. B. Singh
Abstract: In this study reliability analysis of non-repairable weighted k-out-of-n: G (F) systems by incorporating uncertainties namely aleatory and epistemic have been considered. To remove these uncertainties the combination of mass distribution, fuzzy exponential distribution and belief universal generating function have been used. The failure rate (λ) of each component is taken as trapezoidal fuzzy number. Using the proposed method fuzzy reliability function of each component have been calculated and then distributed masses among the components. With the help of these masses reliability and MTTF of the proposed system have been obtained. At last a numerical example is taken to understand the proposed method.
Keywords: Weighted k-out-of-n system, fuzzy exponential distribution, belief universal generating function, system reliability and mean time to failure.
Double acceptance sampling plan based on the Burr type X distribution under truncated life tests
by Wenhao Gui, Xinman Lu
Abstract: In this paper, we propose a double acceptance sampling plan for the Burr type X distribution when the lifetime experiment is truncated at a predetermined time. The zero and one failure scheme is considered. The minimum sample sizes of the first and second samples necessary to ensure the specified median life are obtained at the given consumer's confidence level. The operating characteristic values are analyzed with various ratios of the true median lifetime to the specified life of the product. The minimum ratios of the median life to the specified life are also presented. We illustrate the double acceptance sampling plan with a numerical example.
Keywords: Double acceptance sampling plan, operating characteristic function value, producer's risk, truncated life test, Burr type X distribution.
Research on Interval triangular fuzzy Multi-attribute Fault Diagnosis Methods Based on the Grey relation grade
by Liu Yin, Lu Zhaoqin
Abstract: Considering the fuzzy multi-attribute problems of components' failure information, a fault diagnosis model of a Bayesian network based on the interval triangular fuzzy multi-attribute decision method was built. First, the fault multi-attribute hierarchies were represented as a Bayesian network structure by Bayesian network causal dependencies, which reduced the complexity of the multi-attribute hierarchy. Second, in the condition that weight information is completely unknown, grey correlation optimal models were constructed based on the grey correlation analysis method. Furthermore, faulty components were sorted and the component with the the highest value was optimized, and the calculation method of interval triangle fuzzy multi-attribute decision based on the grey correlation was given, which realized the fault diagnosis of the system fuzzy multiple-attribute problem. Finally, the method was applied in an analysis of a case of fault diagnosis on a CNC machine tool servo system with a low voltage alarm, which verified the effectiveness of the method.
Keywords: Grey correlation degree;Interval triangle;multiple-attribute decision;Bayesian network; Fault diagnosis
A New Model for Selecting Sites for Chain Stores in China
by Chih-ming Hsieh
Abstract: Retail chains, particularly those with small stores of approximate area 150180 square feet, are expanding aggressively in China. Because studies and essays related to this phenomenon are rare, this study evaluated the ideal locations for such chain stores. The three major aspects of site selection are population structure of the trade area, traffic-carrying capacity, and attraction of the facilities; these aspects can be decomposed into 10 site-selection elements: crowd flow in front of the retail store, resident population, target number of clients, complementary stores, mutually exclusive shops, advantages in establishing the store, disadvantages in establishing the store, actual usable space in the store, ratio of rent to gross profit volume, and rate of investment return. Multiple stepwise regression was applied in this study. The evaluation model provides retailers a fast and reliable store selection method for acquiring profitable new stores.
Keywords: Retail chains; Site selection; Stepwise regression; Chain stores.
Critical component identification and autonomous maintenance activities determination using Fuzzy Analytical Hierarchy Process (FAHP) method
by Ahmadi Musman, Rosmaini Ahmad
Abstract: Autonomous maintenance (AM) is a preventive maintenance (PM) strategies that focuses on the man-machine relationship towards effectively performing the following activities: cleaning, lubricating, and tightening. The previous literature found that most of the applications and implementations of AM strategy were only discussed as a subset of Total Productive Maintenance (TPM) and from a managerial perspective. This paper highlights the technical issue of AM strategy implementation by proposing an AM decision model using the Fuzzy Analytical Hierarchy Process (FAHP) method to identify the critical components and to determine the right AM activities. A case study that used a lathe machine was used to validate the model. The model assists the maintenance engineering team to systematically implement an AM strategy with their production assets. The benefit of this model is that it minimizes the maintenance costs and time by identifying and determining the right component to be focused on for maintenance as well as the right maintenance activities to be carried out.
Keywords: Autonomous maintenance activities, Fuzzy Analytical Hierarchy Process (FAHP), critical components
Analysis of Maximal Covering Location-Allocation Model for Congested Health Care Systems in User Choice Environment
by Mahsa Pouraliakbari, Mohammad Mohammadi, Abolfazl Mirzazadeh
Abstract: This paper attempts to shed light onto the formulation and the solution of a probabilistic maximal covering location model for determining the optimal location of facilities in congested health care systems with referral hierarchical structure. We will address health care systems operating in a competitive setting and when the customers choose the facilities they patronize, by the travel time to the hospitals and service costs at each hospital. The hospitals have several low-level sections for offering low level services (such as primary services) and several high-level sections for offering high level services (such as professional services) and the patients will refer to different sections of hospitals according to their requirements and their physical conditions. Our objective is to minimize the total amount of demand that is lost in the system. To solve the model, two meta-heuristic algorithms, including population based simulated annealing (PBSA) and ant colony optimization (ACO) have been executed and analyzed using statistical test and TOPSIS method to determine which algorithm works better.
Keywords: probabilistic maximal covering location problem; congested system; health care system; user choice environment; hierarchical structure; queuing theory; competitive environment; population based simulated annealing; PBSA; ant colony optimization; ACO.
Resource Optimization for an Automobile Chassis Manufacturer through Value Stream Mapping enhanced with Simulation Technique and Constraint Programming
by Shyamal Samant, Varinder Kumar Mittal, Ravi Prakash
Abstract: Incorporation of lean thinking has become an essential part of any manufacturing system, as reducing waste leads to cost savings and hence competitiveness of the company. Value Stream Mapping (VSM) which leads to cost savings is a part of the portfolio of tools to achieve lean orientation in manufacturing systems. Lean implementation starts with the application of VSM to an assembly line; however, it has various limitations. VSM being a pencil-and-paper technique is a static tool. It does not provide a dynamic view of the situation. There is need to enhance the VSM through discrete-event simulation (DES) technique (using Arena
Keywords: Value Stream Mapping, Lean Thinking, Resource optimization, Constraint Programming
MANUFACTURING FLOW TIME ESTIMATION USING MODEL- TREE INDUCTION APPROACH IN A DYNAMIC JOB SHOP ENVIRONMENT
by V. Thiagarajan, T. N.Srikantha Dath, Chandrasekharan Rajendran
Abstract: We describe an application of a supervised learning method, model-tree induction, for the estimation of flow time in a dynamic job shop. An attempt is made to incorporate transfer batching as order- review and order-release policy in the simulation model, whereas much of previous research appears to have ignored order-review and order-release policy. The computational evaluation performance shows that the prediction accuracy of the model-tree induction method is superior to traditional methods such as total-work-content method and dynamic-total- work-content method in estimating the flow time. This research work has been carried out with an open-source software in order to demonstrate the use of machine learning tools by resource-constrained small-and medium-enterprises in their decision making process.
Keywords: simulation; machine earning; data mining; model-tree induction;manufacturing flow time estimation.
Performance comparisons of utilization of silo and non-silo systems in mechanizing fertilizer application in Malaysian oil palm plantation industry
by Muhammad Esyam Adip, Darius El Pebrian
Abstract: The labor shortage and rising of fertilizer prices that is being faced by the oil palm plantation industries in Malaysia becomes challenging problems in their operations to achieve sustainability of economic and productivity. Thus, mechanization has been adopted as an alternative approach to replace labor and at the same time to save costs in fertilizer application. This study was conducted to compare field performances of silo and non-silo systems in mechanizing fertilizer application in Malaysian oil palm plantation industry. The silo system uses a temporary silo for storage the fertilizer in the field, while the non-silo system applies directly the fertilizer from the storage house. The results showed that the silo system gave a field capacity of 3.77 ha h-1 or 1.5 times greater than that of 2.49 ha h-1 of the non-silo. The total cost of silo was USD3.31 ha-1 or 5.74% higher as compared to USD3.12 ha-1 of the non-silo. The findings are only applicable for flat and undulating areas. Nonetheless, both systems can be considered as low-cost systems as compared to the manual system, which requires a total costs ranging from USD3.66 ha-1 to USD4.28 ha-1 for fertilizing operation. The silo system is recommended for those plantations which need a timeliness of fertilizer application in the field.
Keywords: fertilizer application, silo and non-silo, mechanization system, oil palm plantation industry, farm machinery
Model-Based Collaborative Development of Manufacturing and Control Systems
by Filmon Andemeskel, Daniel Semere
Abstract: This paper presents a collaborative model-based development method for a manufacturing system and its control system. The method is aimed towards improving the traditional manufacturing and control systems development approaches that are often done independently and in sequence. First the interactions and dependencies in the multi-disciplinary development process are identified. Depending on the desired the level of abstraction, a system is modelled in a discipline neutral modelling language from which domain specific models are automatically transformed to a language of a target modelling environment. These models are then used as a basis for further development by domain experts. As an illustrative case, SysML is used for modelling of a high level system concept of a manufacturing cell. The subsequent modelling, simulation and the associated verification, validation and control code generation steps are described.
Keywords: Collaborative development, co-modelling & co-simulation, PLC, virtual commissioning.
Enhancing remanufacturing efficiency in Malaysia through a knowledge support system: A case study of brake calipers
by Loh Wei Lie, Nurhasyimah Abd Aziz, Dzuraidah Abd Wahab, Mohd Nizam Ab Rahman, Che Husna Azhari
Abstract: Implementing remanufacturing is certainly a challenge to the new industry in many developing countries since this most promising end of life recovery option requires products to be returned to `as new` condition. The remanufacturing process requires specific knowledge, skill and the experience of the operators, hence the need for a knowledge based system to ensure an efficient reprocessing of the ELV components. For the purpose of this study, a prototype support system for the remanufacturing of a brake calipers was developed. Knowledge and experience on the disassembly and reprocessing of brake calipers and the remanufacturing of ELV components in general are gathered from a case study in a local company involved in repairing of brake calipers. Based on knowledge gathered through interviews, observations and comparison with practices documented by established practitioners, a Graphical User Interface (GUI) support system for the remanufacturing of brake caliper was proposed.
Keywords: End of life vehicle; remanufacturing; reuse; knowledge and skills; knowledge support system; brake caliper; inspection; disassembly; reprocessing; National Automotive Policy.
Ranking of companies regarding to the effective factors on technology transfer using FAHP and Fuzzy TOPSIS techniques
by Shima Arabzadeh
Abstract: The purpose of this research is to realize how organizations have been sustaining their growth through applying technology transfer factors. Regarding the thematic nature of a research model, experts opinion of the oil industry and companies in the oil industry have been examined in the current study which included : 1) oil pipeline and telecommunication company ; 2) oil products distribution company; 3) National Gas Company in Semnan and Khorasan province, all have been brought for this research as a statistic population. Numbers of experts participating in the study were 30 persons who were interested in improving this discussion. The main tools used for gathering the data in this study were company records and a questionnaire. In this study, companies were ranked regarding to sub-scales related to different levels of factors effective on technology transfer of the oil industry by using FAHP and Fuzzy TOPSIS. The results obtained from both methods indicate that the oil pipeline and telecommunication company are more important than the national gas company, and the oil product distribution company. The results obtained from fuzzy AHP technique, according to the technology transfer factors, indicate that the technological feature is of most importance for the oil industry than the organisational feature, personnel feature, and industrial feature. According to the technological feature scale, it is concluded that diffusion is the most important factor among the other factors.
Keywords: Technology transfer, the effectiveness of technology transfer influential factors, FAHP, Fuzzy TOPSIS
Measuring architecture and design efficiency for enterprise applications
by Viral Gupta, Parmod Kumar Kapur, Deepak Kumar
Abstract: The efficiency of architectural and design attributes in enterprise applications plays a very crucial role in the successful implementation. These attributes are the building blocks of the software program that influence the overall quality and customer satisfaction. Despite of various controls and metrics available in quality management discipline, the implementation of enterprise applications tend to fail or do not accomplish the desired level of efficiency in terms of architectural and design attributes. This research paper presents a two-way framework that is based on Analytic Hierarchy Process for measuring and controlling these attributes across various stages in the implementation life cycle. The proposed framework calculates the utility measure for these attributes, which is an indication of performance and efficiency. An experiment was conducted on an enterprise application project and the utility measure was derived using the proposed framework at various stages. The utility measure obtained from the framework demonstrated the improvement in the performance and efficiency of architectural and design attributes by forty five percent.
Keywords: Architecture; Design; Utility Measure; Analytic Hierarchy Process; AHP; Enterprise Applications; Quality; Two-way Assessment.
A STATISTICAL MONITORING STRATEGY FOR A PULP AND PAPER INDUSTRY
by Pulkit Rana, Anupam Das, Swarnambuj Suman, Jhareswar Maiti
Abstract: The current article features the endeavour to develop a monitoring strategy for paper and pulp industry. The process of making pulp involves treating agriculture waste such as wheat straw and bagasse with numerous chemicals and other agents. The complexity involved in the production of better quality pulp warrants the close monitoring of the process characteristics associated with the process. Hence a process monitoring strategy needs to be developed for the same. Partial Least Square Regression (PLSR) which is a multivariate statistical projection based technique is used for building the process representation which aids in the simultaneous monitoring of multiple correlated characteristics. Individual Hotelling T2 chart has been developed to monitor each grade of paper being produced. However this leads to implementation of different control charts for different grades of paper adding to the dexterity of the methodology. Hence in order to cater the aforementioned state of affairs the methodology hence developed is further extended to develop a combined control chart to monitor all the grades of paper simultaneously. Furthermore a comparative study of the competence of the developed unified control chart with respect to the individual charts is done. The unified chart hence developed can be considered as proper approximation of the individual control charts to a certain extent.
Keywords: Process monitoring; Partial Least Square Regression; Hotelling T2 chart; diagnostic statistic; Unified control chart
An optimization approach for finding an optimal pricing in a hybrid manufacturing/remanufacturing system
by Ankita Ray, Sandeep Mondal
Abstract: Hybrid manufacturing/remanufacturing in closed loop manufacturing system (CLMS) has gained considerable attention in industry over past few years due to environmental concern. Remanufacturing of used products basically includes activities like acquisition of used product, reverse logistics, cleaning, inspection, reassembly, disposal of unused material, and remarketing. Determination of selling prices of remanufactured product is also complex and an important decision making area as the profitability of remanufacturing business is significantly dependent on it. Under the above circumstances in this research paper, a profit-maximization model is developed to optimize selling price of new products and used products using Genetic algorithm. OEM (original equipment manufacturer) sells remanufactured products in place of brand new products as there is no quality difference between them and also sells refurbished products and spare parts into secondary market. In this paper a numerical example and sensitivity analysis has been performed.
Keywords: Closed loop supply chain; pricing policies; profit maximization model; Genetic algorithm;
A novel hybrid approach based on fuzzy DEA AHP
by Owais Torabi
Abstract: The data envelopment analysis (DEA) model is a non-parametric programming technique that helps to efficiency evaluating for every decision making units (DMUs) with multiple inputs and multiple outputs. In traditional DEA model, we need crisp data. But in the real world, most of the data are imprecise and uncertain. A major cause of uncertainty related to the non-quantifiable, incomplete and unachievable information. For this reason, fuzzy logic and fuzzy sets developed in different models of DEA.
In this paper, a new hybrid model is developed for performance evaluation problems ranking of DMUs, with multiple inputs and fuzzy outputs. To achieve the best ranking of DMUs, fuzzy analytical hierarchy process (FAHP) is applied. Solving FAHP ends up in a full ranking of DMUs. Finally, to illustrate the proposed model an example is presented.
Keywords: Fuzzy data envelopment analysis (FDEA); efficiency analysis; fuzzy analytical hierarchy process (FAHP)
Productivity Enhancement by Component Oriented Line Balancing Method
by A John Rajan
Abstract: The problem of balancing a production line has been one of the typical
complications in the field of industrial engineering. An unbalanced production
line associates with the downfall in productivity. Since productivity is the
primus motor of income in any firm, the above problem cannot be over
sighted. In this paper a similar problem is being faced by a company which is
unable to cope up with the increasing demands of their product. The past data of
component manufacturing process, resources required and the time taken is
collected, when this data is analysed, constraints are observed in the testing
machine of the production line. The elimination of bottleneck in this line is
needed in order to escalate the productivity. The intended rate of production is
achieved through Component Oriented Line Balancing (COLB) approach. In this
method the number of workstations is increased and hence bottle neck is
removed. The comparison of the data before and after the implementation of
Component Oriented Line Balancing shows a simultaneous improvement in the
productivity and reduction of labour cost.
Keywords: Line balancing, bottlenecks, productivity, cycle time, component oriented
Modified Improved Genetic Algorithm to minimize Tri-Objective functions in a Textile Mill
by Jeyakkannan Sundararajan, Prabaharan T
Abstract: Efficient scheduling has become essential for manufacturing industries to survive in today's competitive business environment. Flow shop scheduling problem with processing times in textile yarn manufacturing mill is considered in this paper. The objective is to minimize the tri objective function of makespan time, meanflow time and machine idle time by using the exact sequencing method. To solve this problem Modified Improved Genetic Algorithm (MIGA) is proposed in this paper wherein multiple cross over operators and multiple mutation operators are fine tuned to obtain the above performance measures and the results show that the proposed algorithm can provide better results in textile industry problems when comparing with the results obtained through Genetic Algorithm (GA) and Improved Genetic Algorithm (IGA).
Keywords: Flowshop scheduling, make span, mean flow time, machine idle time,tri objective function, Modified Improved Genetic Algorithm
Closed form models for dwell point locations with turnover based storage assignment policy
by Faizul Huq, Trevor Hale, Heather Lutz, Nikhil Pujari
Abstract: This study investigates where an idle storage-retrieval device should dwell (locate) to minimize the expected response time of its next transaction for both an Automated Storage/Retrieval System (AS/RS) and an Automated Storage Carousel (ASC). A review of the relevant literature showed that previous attempts to obtain the dwell point location only considered a randomized storage assignment policy. This research proposes that under a myriad of operating conditions, the problem can be formulated as a p-median location problem on a tree network to incorporate the turnover based storage assignment policy.
Keywords: Dwell point location; facility location; location science; turnover-based storage assignment policy.
An Empirical Study to Improve Software Quality through Design Patterns
by Khalil Elbaz, Allaoua Chaoui
Abstract: Numerous elements influence the quality of software systems. One of these elements is the use of design patterns. This paper examines the influence of design patterns on quality requirements in particular maintainability. Improving the maintainability of software systems provides a higher opportunity for recovery because maintenance costs can use 60 - 80% of the complete budget of proprietorship of software systems. In addition, if the maintainability of the software system is poor, the destruction of the product will increase and the system will rapidly lose its importance to stakeholders. In this context, we propose a pattern guided approach to improve the maintainability of software products. Maintainability is measured by certain factors. We focus in this article on the observer and the Fa
Keywords: Maintainability, Design patterns, Tactics, Metrics.
An updated literature review of agile manufacturing: classification and trends
by Apriani Soepardi, Pratikto , Purnomo Budi Santoso, Ishardita Pambudi Tama
Abstract: In contemporary manufacturing area, agility is considerably acknowledged as an emerging issue to react to dynamic market environment changes. The implementation of agile manufacturing system proved to be efficient to acquire a competitive advantage. Since the agile manufacturing (AM) concept was popularised in 1991, there is an growing recognition by practitioners and academics. The aim of this study is to perform an analysis of AM research in order to update the literature review, give the current discussion regarding the trends and note the suggestions for the future directions of AM research. In this paper, we provide a wide coverage of excessively citations on AM from 1991 to 2015. The papers are classified in AM conceptual frameworks, agility assessment, agility achievement, merging lean and agile concepts, and adopting AM on Small Medium Enterprises. Furthermore, a category scheme to organize the journals is proposed and equipped by summary statistics presentation. The study results of the literature review is expected to assist development in the AM research.
Keywords: agile manufacturing; agility assesment; conceptual framework; leagile concept; sustainable manufacturing.
Availability optimization of multi-state series-parallel systems with human failures
by Seyed-Sirvan Karimi, Mahdi Karbasian, Reza Tavakkoli-Moghaddam
Abstract: Nowadays, the availability of systems and tendency to commit errors has become an important issue during the design of many engineering systems. Humans play a key role in the overall availability of engineering systems because many systems are interconnected by human links to a certain degree. Using the redundancy strategy and adding the additional components are considered as a method of enhancing the availability of systems. Multi-state system models allow both the system and its components to assume more than two levels of the performance. Obviously, if the system is multi-state, methods to achieve the availability values of the system have an important role. In this paper, a heterogeneous redundancy optimization problem for multi-state systems subject to human failures is formulated to minimize the system cost with the constraint, in which the system availability is greater than a desired level. Human failures are recognized with a fault tree analysis (FTA) method. Components in the same subsystem can be different, and both components and the systems are multi-state. The universal generating function (UGF) algorithm is used to compute the system availability and the genetic algorithm (GA) are used to optimize the system structure. To solve the model, MATLAB software is used, and to illustrate the credibility and applicability of the model, a case study is offered and analyzed. The result of the solved model is corroborated and shows the efficiency of the used methods.
Keywords: human failures; minor and major failures; multi-state systems; UGF algorithm; genetic algorithm.
Use and relevance of quality, safety and environment management tools and techniques: an empirical investigation, case of Moroccan companies
by Mariyam Moumen, Houda ELaoufir
Abstract: A large number of tools and techniques to improve the quality of products, assess environmental impacts, and manage the risks to health and safety at work, are available. It is interesting to characterize them in order to better understand their relationship and their relevance in different situations. Focusing on the level of use of these tools by responsible persons and target the most mentioned that seem most appropriate to different situations. In this paper, we conduct an empirical study to examine the level of use of quality, safety and environment management tools and techniques. To do this we use the responses of animators and representatives of QSE management systems in 34 Moroccan companies at least certified according to ISO 9001. After a diagnosis of the most serious, common and repetitive health and safety risks of all the companies surveyed, we discuss the action plans that are available to the Moroccan companies to evaluate the different health and safety problems at work. Finally we integrate all QSE tools and techniques encountered in a continuous improvement PDCA.
Keywords: Quality; Safety; Environment; IMS; Tools; Morocco
A combination of range-adjusted measure, cross-efficiency, and assurance region for assessing sustainability of suppliers in the presence of undesirable factors
by Reza Farzipoor Saen, Kamyar Hosseinzadeh Zoroofchi, Payman Bayat Lari, Majd Azadi
Abstract: Assessing sustainability of suppliers and selecting the most sustainable supplier are the most important activities in sustainable supply chain management (SSCM). Data envelopment analysis (DEA) is frequently used to select suppliers. We extend range-adjusted measure (RAM) model as one of the DEA models. We mix different models of RAM as well as cross-efficiency and assurance region methods when undesirable factors exist. In a case study, we show applicability of the proposed model.
Keywords: Sustainable supplier selection; Data envelopment analysis (DEA); Range-adjusted measure; Cross-efficiency; Assurance region; Undesirable factors.
AN OPTIMAL JOINT MAINTENANCE AND SPARE PARTS INVENTORY MODEL
by Parag Siddique, Huynh Trung Luong, Muhammad Shafiq
Abstract: Optimized maintenance of plant machineries is one of the important tasks to reduce plant operating cost. To carry out these maintenance tasks smoothly, development of spare parts inventory policy is the most prioritized issue. This research aims at the derivation of a joint maintenance and spare parts inventory model for a multi-component system. The decision variables are the order quantity and the ratio of ordering interval to preventive maintenance interval. We used block based maintenance policy and periodic review inventory policy in this study. At first, a cost function is developed assuming that failure occurrences follow Poisson process with a constant failure rate and machine failures are non-repairable. Second, the model is further expanded for the case when failure occurrences follow non-homogeneous Poisson process and machine failures are repairable. The applicability of the developed models is demonstrated by numerical examples. Sensitivity analysis is also conducted to examine the effects of input parameters.
Keywords: maintenance; spare parts; block-based maintenance; periodic review inventory; non-homogeneous poisson process; repairable system; non-repairable system
Cost optimization analysis of retrial queue with K optional phases of service under multiple working vacations and random breakdowns
by P. Rajadurai, M.C Saravanarajan, V.M. Chandrasekaran
Abstract: In this paper, we consider a cost optimization analysis of M/G/1 retrial queue with k optional phases of service under multiple working vacations and vacation interruption, where each phase consists of an optional re-service. An arriving customer may balk the system at some particular times. When the orbit becomes empty at regular service completion instant, the server goes for a working vacation. During a working vacation period, the server works in lower service rate. The normal busy server may get to breakdown and the service channel will fail for a short interval of time. We analyze the steady state probability generating function for the system size by using the supplementary variable method. Some important system performance measures are obtained. Finally, some numerical examples and cost optimization analysis are presented.
Keywords: retrial queue; re-service; multi phase service; multiple working vacations; vacation interruption;
An Experimental Investigation on Electro Discharge Machining (EDM) of Inconel 601
by Saurav Datta, Chandramani Upadhyay, Rahul Kumar, Siba Sankar Mahapatra, Bibhuti Bhusan Biswal
Abstract: The paper reports an experimental investigation on Electro-Discharge Machining (EDM) of Inconel 601 using Copper electrode tool. Based on L27 Orthogonal Array (OA), experiments have been conducted by varying five controllable process parameters [viz. peak current (Ip), Pulse-on Time (Ton), Gap Voltage (V), Duty Factor ( ) and Flushing Pressure (Fp)] within selected experimental domain. The following machining responses: Material Removal Rate (MRR), Electrode Wear Rate (EWR), Roughness Average (Ra) and Surface Crack Density (SCD) (developed on EDMed surface of Inconel 601) have been investigated for each of the experimental runs. Satisfaction function and distance based approach (in conjugation with Taguchis optimization philosophy) has been proposed herein to select the most favourable process environment (parameters setting) to satisfy high MRR, and less EWR, Ra and SCD optimized up to the maximum possible extent. The predicted optimal setting has been compared to that of obtained by exploring grey-Taguchi approach. Apart from parametric optimization, SEM micro-graphs have been analysed as well to infer important observations in terms of surface irregularities (surface cracks, formation of white layer, heat affected zone etc.) on the end product of EDMed Inconel 601 specimens.
Keywords: Electro-Discharge Machining (EDM); Inconel 601; Orthogonal Array (OA); Satisfaction function; Taguchi’s optimization philosophy; grey-Taguchi approach
MX/G/1 State Dependent Arrival Queue with Optional Service and Vacation under Randomized Policy
by Charan Jeet Singh, Binay Kumar, Sandeep Kaur
Abstract: The present study deals with a single server queue with state dependent arrival rates in batches for essential and optional service available in the system. It is considerable that server can avail the at most m vacations under randomized vacations policy. The system is analyzed by using the supplementary variable technique with the assumptions of probability reasoning to study the behavior of the system and various performance indices of queue size distribution are obtained. To discuss the comparative study of exact and approximate waiting times of the units, the maximum entropy principle is used to find the approximate values of the system state probabilities for the queue length distribution. The cost function is also considered to obtain the optimal values of the cost parameters. The numerical results with the illustration are also carried out to validate the analytical results of the system. rn
Keywords: Randomized vacation, Optional service, Supplementary variable, Maximum entropy, Queue size, Optimal cost.
Optimisation of EDM process for MRR, TWR and Radial overcut of D2 steel: A hybrid RSM-GRA and Entropy weight based TOPSIS Approach
by Mohan Kumar Pradhan
Abstract: In this research, a distinct combination of Response Surface Methodology (RSM), Gray Relational Analysis (GRA) with Shannons entropy measurement based technique for order preference by similarity to ideal solution (TOPSIS) method has been suggested to assess, improve and estimate the influence of the process parameters on responses characteristics. Electrical Discharge Machining (EDM), the most versatile and commonly used non-traditional manufacturing process is considered in this study. The pulse current (Ip), pulse duration (Ton), duty cycle (Tau) and discharge voltage (V) were considered as the input parameters, whereas, Material Removal Rate (MRR), Tool Wear Rate (TWR) and Radial Overcut or Gap (G) were considered as the output parameters. This research highlights the development of a hybrid model to correlate the EDM parameters with the response obtained by the Shannons entropy based GRA-TOPSIS method. To justify the research ANOVA has been
used and it is found that the relative closeness was significantly affected by the
considered input parameters and some of their interactions. The R2 value for the
relative closeness was found to be 96.83 %. The ANOVA reveals that Ip is the most influencing parameter with 46.49% contribution followed by Ton, Tau and V with 13.92 %, 7.35 % and 2.8 %, respectively. The interaction of parameters contributes 15.26%. These results provide useful information to control the machining parameters and hence responses to ensure high productivity and accuracy of the EDMed component. Besides,this study can be used as a scientific source for parameter optimization in concerned manufacturing processes.
Keywords: Electrical discharge machining, Material removal rate, Tool wearrnrate, Radial overcut or Gap, Response surface methodology, Grey relationalrnanalysis, Shannons entropy, Technique for Order of Preference by Similarity tornIdeal Solution (TOPSIS)
A Final Note on the Ones Assignment Method and its Variants: They Dont Work
by Eric Landquist, Curtis Reigle, Francis Vasko
Abstract: Recently, Basirzadeh (2012) presented a new algorithm for solving the linear sum assignment problem that is called the Ones Assignment Method. It is similar to the Hungarian Method, but seeks to create, through division, ones in each row and column (instead of zeros as in the Hungarian Method) of the assignment matrix. Subsequent steps are analogous to the Hungarian Method. There have been several papers (Ghadle and Muley (2013, 2015), and Khalid et. al. (2014)), that have suggested modifications to the Ones Assignment Method. In this short paper, we provide a trivial assignment problem and show that neither the Ones Assignment Method nor any of its variants are able to find the optimal assignment to this problem which is obvious on inspection.
Keywords: Assignment problem; Hungarian method; Auction Algorithm; Ones Assignment Method; Optimization; Linear programming; algorithm; counterexample; additive strategy; multiplicative strategy
Price, production and order decisions in a one-manufacturer multi-retailer supply chain with fuzzy costs: Two parameter tuned meta-heuristics
by Mohammad Saeid Atabaki, Abolfazl Mirzazadeh, Saeed Fazayeli
Abstract: This paper develops a mixed integer nonlinear programming model of a one-manufacturer, multi-retailer, multi-period supply chain, where demands of retailers are affected by selling prices and learning curve is considered in production costs. Also, fuzzy concept is applied to cope with uncertainty of cost's parameters. Two meta-heuristic algorithms, namely genetic algorithm (GA) and invasive weed optimization (IWO) are proposed to solve the model. With optimizing parameters of the two meta-heuristics using Taguchi design of experiments, numerical examples showed that the proposed IWO has better performance in comparison with the GA. The IWO, then, is applied to solve the fuzzy model.
Keywords: Supply Chain; Nonlinear; Fuzzy; Genetic Algorithm; Invasive Weed Optimization; Taguchi.
Analytical Model of Information System Development Productivity in Adaptive and Perfective Maintenance Phases
by Kai Huang, Xiaoying Kong, Li Liu
Abstract: This paper presents an analytical model for Information System (IS) maintenance productivity in adaptive and perfective phases. The modelling approach is from economic view point. The productivity model considers the economic value of the maintenance phase, pre-committed fixed cost and variable cost consumed in adaptive/perfective maintenance. Influence factors to the productivity are analysed using simulation. The simulation provides a tool for IS project managers to tune the project parameters to obtain the optimal productivity in adaptive/perfective maintenance phases.
Keywords: analytical model, economic model, maintenance, productivity, IS maintenance management, simulation, software engineering
Energy and Magnetostriction analysis and Nonlinear Model of Magnetostrictive Actuator for Precision Drive
by Huifang Liu, Xingwei Sun, Quan Liang
Abstract: Magnetic hysteresis and eddy-current heating are the most significant disadvantages in giant magnetostrictive materials (GMM). And these properties have an effect on the displacement precision and other working performances of giant magnetostrictive actuator (GMA). To know and solve these above problems fundamentally, the key point is establishing a mathematical model which can describe magnetization hysteresis process and energy loss characteristics for GMM and analyzing the essential reason which causes hysteresis phenomenon. In this paper, on the basis of Armstrong theory and through analyzing the composition of elastic Gibbs free energy, a nonlinear magnetization and magnetostriction model is established. Experimental results show that this model can predict the magnetization property, magnetostriction, magnetic potential orientation, energy loss characteristic and other working performance for GMM well. It is also able to describe the magnetostrictive elongation and output displacement for GMM rod and GMA respectively. Research results will provide a theoretical basis for solving magnetic hysteresis, working precision, and eddy current heating for GMA fundamentally.
Keywords: GMA, Model, Magnetostriction, Magnetic hysteresis
PERFORMANCE ANALYSIS OF A DISCRETE-TIME GEO/G/1 RETRIAL QUEUE UNDER J-VACATION POLICY
by Shweta Upadhyaya
Abstract: We have investigated a discrete-time Geo/G/1 retrial queue under J vacation policy and general retrial times, which can be applicable to many digital systems viz. broadband integrated services digital network (B-ISDN), asynchronous transfer mode (ATM) and circuit-switched time-division multiple access (TDMA) systems. In discrete-time systems, we consider time to be a discrete random variable and measure it in fixed size data units such as machine cycle time, bits, bytes, packets, etc. The server follows J vacation policy according to which as soon as the retrial orbit becomes empty and no new customer arrives then the server may take at most J number of repeated vacations. The server immediately returns from the vacation if at least one customer arrives in the system. The inter arrival time is assumed to be geometric distributed whereas retrial time, service time and vacation time are assumed to be general distributed in the discrete environment. The underlying Markov process is analyzed by using generating function method whereby we obtain various performance measures of interests. We provide stochastic decomposition laws for the system size of the developed model.
Keywords: Keywords: Discrete-time retrial queue, Bernoulli feedback, starting failure, J vacation policy, Stochastic decomposition.
Fuzzy Control of an Industrial Process System using Internet and Web Services
by Hanane Zermane, Hayet Mouss
Abstract: This paper illustrates the development of an Internet-based fuzzy control system of one of complex industrial manufacturing processes, which is cement production. This system can ensure in the same time the remote and the fuzzy control of the process in real time in different cement factories in Algeria. The remote control system contains several tasks and options as diagnosis of alarms generated during the running of workshops, e-maintenance and synchronising different regulation closed loops to guarantee the automated performance. In addition, to evolve the system, we propose firstly, an artificial intelligence technique which is fuzzy logic, where we integrated the fuzzy control of different workshops of kiln and the two mills, which ensures that the system is operational at all times, with minimal downtime. Secondly, we integrated Internet technology, where the remote control via Internet, used for security of human life and rendering it unnecessary for operators to be at the site for maintenance. In addition, when there is a breakdown it is not necessary to send an expert to diagnose and solve the problem because it is difficult to organise visas, flight, etc. Therefore, the proposed system reduces downtimes and travel costs by the possibility of sending reports and transmitting all process data. The process control system contains different operators stations, alarms tables and trends analysis. The operator can execute any operation according to his authentication access. Operators can monitor the process control system in the main control room or via Internet.
Keywords: Process control; Data acquisition; Fuzzy control; Remote control; Reports transmission; Telecontrol.
Fuzzy Goal Programming Approach on Location-Routing Model for Waste Containers
by Salih Aka, Gökhan Akyüz
Abstract: In this study, an application about determining the location of recyclable waste containers was executed in Siteler District part of Konyaalti Municipality in Antalya, Turkey. For this problem, a location-routing model based on fuzzy goal programming was built. The aim of this study was to select optimal location nodes, which serve the maximum number of dwellings from candidate locations nodes and also, to create a minimum-distanced route between selected nodes. The containers of recyclable waste were located on optimal nodes of the route obtained by the mathematical model, which was run for different tolerance ranges and different priority structures.
Keywords: Multi-objective location models, the location-routing problems, fuzzy goal programming
Economic Design of Exponentially Weighted Moving Average Chart with Variable Sampling Interval at Fixed Times Scheme incorporating Taguchi Loss Function
by Ineen Sultana, Imtiaz Ahmed, Abdullahil Azeem, Nitish Ranjan Sarker
Abstract: A Control chart is a graph used to study how process changes over time. The Exponentially Weighted Moving Average (EWMA) chart is highly useful for not only detecting small changes in process parameters but also in inspecting individual unit observations. The objective of this paper is to develop an economic statistical design of the exponentially weighted moving average (EWMA) chart using variable sampling intervals with sampling at fixed times (VSIFT) control scheme considering preventive maintenance and Taguchi Loss function to determine the values of the seven test parameters (i.e., the sample size, the fixed sampling interval, the number of subintervals between two consecutive sampling times, the warning limit coefficient, the control limit coefficient, exponential weight constant and the time interval of preventive maintenance) such that the expected total cost per hour is minimized. A mathematical model is developed to analyze the cost of the integrated model. Nelder-Mead downhill simplex method and Genetic algorithm approaches are applied to search for the optimal values of the seven test parameters for the economic statistical design of VSIFT EWMA chart and Nelder-Mead downhill simplex performed better than Genetic algorithm. A hypothetical example and its solution are provided to have a better understanding about the demonstration of the proposed model.
Keywords: EWMA control chart; VSIFT scheme; Economic-statistical design; Taguchi Loss function; Preventive maintenance; Nelder-Mead downhill simplex method; Genetic algorithm
A Probabilistic Granular Tabu Search for the Distance Constrained Capacitated Vehicle Routing Problem (DCVRP)
by John Willmer Escobar, Rodrigo Linfati, Gustavo Gatica
Abstract: We address the well-known Distance Constrained Capacitated Vehicle Routing Problem (DCVRP) by considering Euclidean distances, in which the aim is to determine the routes to be performed to fulfill the demand of the customers by using a homogeneous fleet. The objective is to minimize the sum of the variable costs associated with the distance traveled by the performed routes. In this paper, we propose a metaheuristic algorithm based on a probabilistic Granular Tabu Search (pGTS) by considering different neighborhoods. In particular, the proposed algorithm selects a neighborhood by using a probabilistic discrete function, which is modified dynamically during the search by favoring the moves that have improved the best solution found so far. A shaking procedure is applied whenever the best solution found so far is not improved for a given number of iterations. Computational experiments on benchmark instances taken from the literature show that the proposed approach is able to obtain high quality solutions, within short computing times.
Keywords: Probabilistic Granular Tabu Search (GTS), Distance Constrained Capacitated Vehicle Routing Problem (DCVRP), Metaheuristic Algorithms, Vehicle Routing Problems.
Empirical analysis of bus travel time reliability: a case study in Shanghai
by Yangbeibei Ji
Abstract: Travel time reliability is one of the most important indications of quality of service in bus systems. The Automatic Vehicle Location (AVL) data of two typical bus routes in Shanghai are used to analyse bus travel time reliability. One bus line is in urban area and the other is in suburban area. Five reliability indices are used to capture the various characteristics of bus travel time fluctuations, which are planning time, buffer time, buffer time index, punctuality index based on routes and deviation index based on stops. The results indicates that peak hours have more obvious impact on travel time reliability and longer distance between adjacent stops causes higher buffer time at off peak hours. Bus in suburban area has more stable travel time than bus in urban area. The travel time reliability control measures are suggested at the end.
Keywords: Bus Travel Time; Travel Time Reliability; Bus Stops; Automatic Vehicle Location Data.
A Simulation Based Multi-Objective Optimization Approach in Flexible Manufacturing System Planning
by Arash Apornak, Sadigh Raissi, Mehrdad Javadi, Neda Ahmadizadeh, Ahmad Kazem
Abstract: In this paper, an attempt has been made to address the optimum set of queues capacity, queues discipline, conveyors and transporter's speed and operational setup times in a common flexible manufacturing system (FMS) with objectives of minimization of average stay time in queues and maximization of throughput simultaneously. Analysis of such issues, especially when the objective functions cannot be described in mathematical terms is a complex task is focused in this paper. Here the mean of five objective functions estimated by fitness functions extracted experimentally using 36 scenarios on a valid computer simulation model. Under equal weights, the exact solution attained by the Lingo software and optimum process setting achieved. The applicability of the new approach is ascertained through a case study involving the optimization of real engineering system and presented using the proposed approach.
Keywords: Design of experiment (DOE); Response Surface Modeling (RSM); Multi-objective optimization problem (MOP); Flexible Manufacturing system (FMS); Simulation
Modeling and Optimization of Process Parameters of Electrical Discharge Diamond Drilling of Nimonic Alloy-An aerospace Material
by UMacharan Singh Yadav
Abstract: An accent to existing electrical discharge machining (EDM) processes, the present authors have endeavoured to develop altogether a new process termed as electro-discharge diamond drilling (EDDD) and experimented with it for making the holes in nimonic alloy. This EDDD process together encompasses the concept of conventional twist drill, abrasion (micro-cutting) and electro-erosion. A hybrid approach of comprehensive models have been developed to overcome the usual difficulties of the lack in correlation between response parameters of material removal rate (MRR), average surface roughness (Ra), and average circularity (Ca), which confirm with adequacy of 99% confidence by Analysis of variance (ANOVA). The developed model consist of taguchi methodology (TM) coupled with response surface methodology (RSM) and has been termed as TMRSM. The model correlates the effects of interactions as well as of higher order of considered input parameters of tool electrode rpm, gap current, pulse-on time and duty factor. Thereafter, multi-objective optimization (MOO) of the EDDD parameters has been done with the combination of grey relational analysis (GRA) and principal component analysis (PCA) methodology and termed it as GRAPCA. In this methodology, the reference values of central composite rotatable design (CCRD) matrix of RSM model have been used to determine the values of grey relational grades, so as to further determine the values of optimum level of input parameters. The used hybrid EDDD process of machining along with using the hybrid approach of TMRSM as well as GRAPCA methodology for modelling and MOO is successful.
Keywords: Electrical discharge machining; Electrical discharge diamond drilling; Grey relational analysis; Principal component analysis; Response surface methodology; Taguchi methodology.
Application of logistics principles in management of travel agency
by Katarína Culkova, Erik Weiss, Andrea Rosova, Roland Weiss
Abstract: The contribution is focused on the application of logistic management algorithms for Travel agency sector. In the introduction the contribution explains the current state of the problem. As a methodology there is flash analysis, systems analysis and micro logistics analysis. The flash analysis points to the current position of the company on the local market, localization, its products, customers, competitors, mission, vision and strategic goals for the future. System analysis shows ongoing systems in the company. Results of contribution show algorithms of major processes in the company and a micro logistic model of the company. As a result of contribution measures are proposed, as for example a new Web site, modern reservation system and booking accounting system.
Keywords: travel agency; algorithm; flash analysis; system analysis; micro logistic model of the company; Slovakia
Unreliable Retrial Queue with Loss and Feedback under Threshold-based Policy
by Chia-Jung Chang, Jau-Chuan Ke, Fu-Min Chang
Abstract: In this paper, we consider an M/M/1 unreliable retrial queueing system with geometric loss and feedback under the threshold-based policy. Customers arrive at the system according to a compound Poisson process, and they are served immediately if the server is free; otherwise, they will enter a retrial orbit and form a single waiting line. After the customer is served completely, he may decide either to leave the system or to join the retrial orbit again for another service. If the server is found busy, the customer may either leave the system or join the retrial orbit for getting service. The server may be broken down at any time during the server is operating. When the server is broken down, it is not able to be repaired immediately until the number of customers in the system reaches a specified threshold value. The retrial system is modeled by a quasi-birth-and-death process, and some system performance measures are derived. The formulae for computing the rate matrix and stationary probabilities are derived by means of matrix-analytical approach. We obtain the optimal threshold value and the optimal service rate simultaneously to minimize the cost function of the system.
Keywords: retrial queue, quasi-birth-and-death, matrix-analytical.
Using the knowledge base and Fuzzy Inference System to estimate the safety factor in calculating the number of the Kanban cards
by Farzad Firouzi Jahantigh, Ali Noroozian, Ali Daneshi
Abstract: There are many studies in the field of using fuzzy logic in estimating the logistic computational parameters. In the most of these studies, the proposed model is too large and too complicated which contains a lot of parameters. These issues make the proposed models hard to use in many industries. In this article, the safety factor considered in Kanban card calculations named Kanban safety factor and its relationship with fuzzy theory are addressed. Since, Kanban safety factor is obtained using expert judgments, there is uncertainty in it. Therefore, a practical fuzzy method is introduced in this article to calculate Kanban safety factor. The method is efficient due to its simple calculations and comprehensive due to its ability to consider all parameters that affect Kanban safety factor. The new proposed fuzzy method is implemented in a warehouse of Iran Khodro Corporation of Iran which resulted in remarkable improvements.
Keywords: Fuzzy knowledge base; fuzzy inference engine; Kanban; Kanban safety factor; Fuzzy membership functions.
A Decision Making using Data Envelopment Aggressive Formulation and Theory of Constraints to Enhance the PVC Production Line Performance
by Mohammed Shurrab, Abbas Al-Refaie, Nabeel Mandahawi, Shorouq Shurrab
Abstract: Bottlenecks and systems productivity are interrelated domains such that small changes in the bottlenecks could have a huge effect on the systems productivity. This research expounds a managerial case study combined a decision making data envelopment analysis (DEA) technique with the theory of constraints (TOC) systematic approach to a Polyvinyl Chloride (PVC) pipes production line. The true bottleneck was the low efficiency rate of the socketing machine which made the PVC pipes flow difficult during the production process. Four scenarios/solutions were applied to break the bottleneck constraint. DEA was utilized to recognize the optimal solution and make a proper decision. Upgrading the constraint, which was the last resort of TOC implementation, was the optimal solution. The deliverable of this solution was a significant enough performance improvement to break the constraint in the PVC production line. Although the optimal solution increased the incurred cost by 20%, it enhanced the number of the PVC pipes that are produced annually by 21%, increased the line throughput from 0.3 pipe/min to 1.15 pipe/min, and increased the system utilization by 19 % compared to the current situation scenario.
Keywords: Theory of Constraints; Simulation and Bottleneck Analysis; Process Based Costing; Data Envelopment Analysis; Decision making; and PVC pipes.
Application of Multi-Objective Genetic Algorithm to Aggregate Production Planning in a Possibilistic Environment
by Shahed Mahmud, Md. Sanowar Hossain, Dr. Md. Mosharraf Hossain
Abstract: The present study is to develop an interactive possibilistic environment based genetic algorithm for multi-product and multi-period Aggregate Production Planning (APP). APP is the prerequisite in order to make material requirement planning and/or capacity requirement planning accurately. The present study attempts to minimize the production cost and the rate of changing in labor level where production costs, backordering cost, labor level changing cost, demand are considered as imprecise parameters. It is noted that all these imprecise parameters are defined by the triangular possibility distribution. As the overtime production capacity is the fraction of available regular time production capacity, it is defined separately to make the result more acceptable. The proposed methodology is finally applied to demonstrate an industrial case in order to justify the feasibility. The solution obtained by the proposed methodology is compared with other solutions in context with computation efficiency and solution practicability.
Keywords: APP, Imprecise Parameters, MOGA, Possibilistic Environment, Practicability
Prediction of temperature variations using Artificial Neural Networks and ARIMA model
by Ali Namazian, Masoud Ghodsi, Khaled Nawaser
Abstract: Hydrologic processes modeling is a difficult but important affair, these are caused by parameters mutual effects, firstly because the reciprocal effects are numerous, and secondly the parameters interactions to create a complicated system. To predict hydrologic factors such as temperature, rivers flow, quantity of rainfall, air humidity and so on, for design and utilization water sources systems are necessary based on consideration of past and recorded statistical data, in configuration of time and place series. Time series analysis is a traditional prediction method, which is based on two assumptions, stationary and linear, non linear tendency is developed, too, in recent years. An artificial neural network is another prediction method, which showed to have proper ability for time series prediction in some cases. This paper in addition to reviewing two methods of variations of temperature abilities, namely Associated Related Integrated Moving Average (ARIMA), and Artificial Neural Networks (ANN), also compared both methods with each other for variations of temperature prediction of Gorgan city between 1970 to 2010 in Iran. The results indicated ARIMA method presented better estimations than ANNs estimations in relation to data with alternative processes of increasing and decreasing.
Keywords: prediction, artificial neural networks (ANN), Associated Related Integrated Moving Average (ARIMA)
Combat readiness evaluation of a fighter-jet using reliability and cluster analysis
by Panagiotis Tsarouhas
Abstract: We perform reliability analysis on a fourth generation fighter aircraft by taking into consideration its real flight conditions. The collection of the actual failure data was extended over a period of three years. Furthermore, the reliability function, the probability density function, the hazard function were estimated. The time between failures for all aircraft subsystems was evaluated. It was found that half of the failures were attributed to the engine, fuel, and electrical power subsystems. Overall, engine failures were more frequent and thus a quality analysis was undertaken. Commonalities of failure parameters were identified with a cluster analysis and were grouped in a dendrogram. Future research should look to further develop this concept for the evaluation of other types of military or civilian airplanes. This study may encourage air unit technical personnel to introduce a new combo problem-solving approach to systematically remove jet reliability blockers.
Keywords: Reliability, statistical analysis, failure data, fighter aircraft, cluster analysis
Using a Fuzzy MCDM Approach to Measure Project Complexity: A Case Study
by Ehsan Pourjavad, Rene Mayorga
Abstract: Evaluating project complexity is the main means for successful projects and can play an important role in improving the project management of companies that take on multiple projects simultaneously. Despite the importance of this subject, there are few studies in this field and project managers have not paid a great deal of attention to it. In this paper, an exploratory approach has been taken to identify key project complexity criteria which have been narrowed down to the following; project size, project variety, project interdependency, and project context-dependence. Also, a Multiple-Criteria Decision-Making (MCDM) method based on a Fuzzy Analytical Hierarchy Process (FAHP) is proposed to evaluate project complexity using the chosen criteria. Employing the Fuzzy AHP method in group decision-making facilitates a consensus of decision-makers and reduces uncertainty. An example of application is presented to display the utility of the model. The results reveal the usefulness of the proposed model in evaluating the project complexity in terms of complexity criteria. The findings also indicate the project variety and the project interdependency criteria have the highest impact on complexity of projects.
Keywords: Project Complexity; Multi-Criteria-Decision Making (MCDM),Fuzzy Analytical Hierarchy Process(FAHP); Evaluation.
The process flow optimization of crankshaft machining considering production logistics
by Xiaohong Lu, Song Wang, Shasha Wang, Lusi Gao, Likun Si
Abstract: In this paper, a typical crankshaft machining of piston compressor is taken as the research object. Based on System Handing Analysis(SHA), according to a series of problems existed in current actual production process, such as excessive materials handling time, Work in Process (WIP) overstock, unreasonable production layout, low utilization rate of equipment, high labor cost etc.., the process flow diagram method is adopted to research processing, handling, parking, waiting and checking processes in crankshaft production logistics. Reliable optimization of the production process is achieved via collection and analyses of time data in process flow. Through the researches on process flow optimization of crankshaft machining considering production logistics, the unreasonable processing technology of the crankshaft production and processing workshop is changed; through detailed analyses and optimization, process flow time of crankshaft production and processing is saved, the production efficiency is improved and the cost is reduced. The work done in this paper can provide reference for other products in process flow optimization of machining.
Keywords: Production logistics; Crankshaft machining; Process flow diagram method; Optimization; System Handling Analysis.
Fractional Order Model Reference Adaptive Control for SCARA Robot Trajectory Tracking
by Samir Ladaci, Yassine Bensafia, Khatir Khettab, Ahmed Chemori
Abstract: This paper proposes a new control strategy to the problem of trajectory tracking of SCARA robotic manipulator system by using a fractional order model reference adaptive controller (FMRAC) for sufficiently smooth trajectories.
Over the few last years the idea of introducing fractional calculus and systems in adaptive control has found a great interest, for the benefits one can win in the performances given by such systems. The main contribution of this paper, is to show that the proposed fractional adaptive controller is able to reduce the delay time and the overshoot existing in classical control approach. Simulation results illustrate the effectiveness of the proposed control approach comparatively to the classical integer order one.
Keywords: Fractional adaptive control; MRAC; SCARA robot; Trajectory tracking; Approximation methods.
Supplier selection using Improved Input Efficiency Profiling with Common Set of Weights (IIEPCSW) model
by Leyla Fazli
Abstract: The cost of the materials, parts and services received from outside constitutes the major cost of a product production. In such situations, purchasing departments can play a key and basic role in expenses reduction. The best suppliers' selection is one of the most important and basic duties of purchasing departments because of the basic role of suppliers performance on quality, cost, delivery and service, etc. Therefore, the use of accurate and efficient techniques to select the best suppliers is out of question. Hence in this study, a new prototype evaluation model called Improved Input Efficiency Profiling with Common Set of Weights (IIEPCSW) model is presented that provides a logical, reliable, consistent and efficient procedure to evaluate the potential suppliers of an item and select the best supplier (Single sourcing) under certain circumstance in single period. This model is a hybrid model based on Input Efficiency Profiling (IEP) model that improves the performance of IEP model and removes its shortages. Also, by validation is shown that IIEPCSW model is efficient and valid.
Keywords: Suppliers selection; Single sourcing; Single period; certain circumstance; Improved Input Efficiency Profiling with Common Set of Weights (IIEPCSW) model; Input Efficiency Profiling (IEP) model.
A novel approach based on relaxation and reduction to solve the capacitated lot sizing problem
by Mayank Verma, R.R.K. Sharma
Abstract: Capacitated lot sizing problem (CLSP) finds its applications in manufacturing, production as-well-as process industries. Typical size of the real life problems is much larger compared to the sizes that can be handled by commercial solvers, as CLSP is an NP-hard problem. Researchers have attempted different variants of CLSP in last few decades and provided many classical, exact, heuristic and meta-heuristic solution approaches. In this paper, we attempt to solve the multi item capacitated dynamic lot sizing problem with backorders and setup times (CLSPBS). We apply Lagrangian relaxation on the material balance constraint, to reduce the problem into several single constraint continuous knapsack problems with upper bound on the real variables. Bounded variable linear program determines the values of real variables. For the negative or positive value of coefficients in the Lagrangian function, we fix the setup variables at zero or one respectively. Thus the reduced problem is solved in polynomial time, as the main effort required is only sorting of numbers. We use the set up variable that are at one, to develop yet another good upper bound. Branch-and-bound procedure benefits immensely by using these bounds to make a warm start.
Keywords: Capacitated lot sizing; Lagrangian; bounded variable linear program; continuous knapsack problem; branch-and-bound.
New heuristic to generate an initial basic feasible solution for the balanced transportation problem
by Youssef Harrath, Jihene Kaabi
Abstract: This paper studied the balanced transportation problem. Many algorithms were developed to solve optimally this problem. The most commonly used method is the Modified Distribution Method (MODI). The MODI algorithm starts by generating an initial basic feasible solution using the Northwest Corner Method (NCM). In general the cost of the initial basic feasible solution generated by NCM is too high and far away from the optimal cost. For this reason, we propose in this paper a new method to generate an initial basic feasible solution to the balanced transportation problem to solve this issue. This method named Global Minimum Method (GMM) was tested and compared with the NCM, the Minimum Cost Method (MCM), the Vogels Approximation Method (VAM), and the optimal cost obtained by MODI. The computational results proved that the new heuristic is promising for small size instances and outperforms all other methods for big size problems.
Keywords: transportation problem; basic feasible solution; linear programming.
Online Fault Diagnosis in Partially Observed Petri Nets
by Liu Jf, Zhou Zh, Wang Zs
Abstract: This paper investigates the fault detection problem for Discrete Event Systems (DES) which can be modeled by Partially Observed Petri Nets (POPN). To overcome the problem of low diagnosability in the POPN online fault diagnoser in current use, we propose an improved online fault diagnosis algorithm that integrates Generalized Mutual Exclusion Constraints (GMEC) and Integer Linear Programming (ILP).We assume that the POPN structure and its initial markings are known, and the faults are modeled as unobservable transitions. First, the event sequence is observed and recorded. Then the ILP problem of POPN is solved for elementary diagnosis of the system behavior. While this system diagnoses that some faults may have happened, we also use GMEC for further diagnosis. Finally, we modeled and analyzed an example of a real DES to test the new fault diagnoser. The proposed algorithm increased the diagnosability of the DES remarkably, and the effectiveness of the new algorithm integrating GMEC and ILP was verified.
Keywords: Fault diagnosis; Partially Observed Petri Nets; Integer Linear Programming; Generalized Mutual Exclusion Constraints.
A novel genetic algorithm for the maximum coverage problem in the three-level supply chain network
by Bahman Naderi, Omid Rahmani, Mohammad Mohammadi, Mehrdad Nourri
Abstract: The maximum coverage problem is one of the most functional location issues. One of the competitive advantages for organizations is efficient and effective designing of supply chain network. On the other hand, given the importance of distribution planning among the levels of supply chain, vehicle routing problem needs to be explored which leads to a significant reduction in costs of supply chain network. The purpose of this research is designing a supply chain network that includes the supply, distribution centers and retailers. It should be noted that the coverage radius is defined for all distribution centers and distribution centers gives any services to retailers that is within the actual coverage. Also, this service is done on routing. Since the classical vehicle routing problem is NP-hard, to solve the problem in small sizes, we used the GAMS software and genetic algorithms and simulated annealing. Finally, the results have been evaluated.
Keywords: The Maximum Coverage Problem; Three-level Supply Chain Network; Genetic Algorithm; Simulated Annealing; Vehicle Routing Problem.
Soft computing method for minutiae-based fingerprint authentication
by Adhiyaman Manikcam, Ezhilmaran Devarasan
Abstract: In this paper, the fingerprint authentication is obtained by using fuzzy logic system which is based on bell shaped intuitionistic fuzzy number. The minutiae points extracted from fingerprint images which are treated as a fuzzy number. The important of the proposed work is to find out the two identical fingerprint images based on minutiae points, from these selects the optimal set and reduce the error points between the images using fuzzy logic system. The fuzzy system provides an adequate description of the proposed algorithm. The uniqueness of this process is consisting of a smaller number of calculations better than previous methods.
Keywords: biometric; fingerprint; minutiae extraction; fuzzy logic; intuitionistic fuzzy numbers; authentication system.
Modeling sustainable supply chain management problem with fuzzy demand based on multi-criteria decision making methods
by Mahnaz Mohebalizadeh, Ashkan Hafezalkotob
Abstract: Nowadays, environmental issues are playing a significant role in our real lives and need to be taken into account in many decision making problems. In order to incorporate environmental concerns into supply chain management problem as one of the most important decision making problems, a new sustainable supply chain model is developed in this paper in which collection/inspection, recycling and returning unsatisfying and for end of life products are examined in uncertain environment. In this regard a multi-objective mixed integer linear programming model with fuzzy demand parameter is proposed in which the flows through the sustainable supply chain network and facilities locations are determined in such a way that four objective functions are optimized including minimizing total cost, minimizing energy consumption, maximizing number of jobs, and minimizing delivery time. Using modified fuzzy parametric programming (MFPP) and weighted metrics as method the solution procedure to solve the developed model, it is implemented on a real case study to demonstrate its capabilities in practical context.
Keywords: Sustainable supply chain; sustainable development; multi objective problem; fuzzy TOPSIS; fuzzy programming.
Influence of process parameters on MRR, kerf width and surface roughness during WEDM on Inconel 718: Performance analysis of electrode tool material
by ANSHUMAN KUMAR, Kumar Abhishek
Abstract: In the present study, an attempt has been made to study the performance of (Brass wire electrode and zinc coated brass wire electrode) wire electrodes in relation to Material Removal Rate (MRR), kerf width and surface roughness of machined Inconel 718 obtained by Wire electro discharge machining (WEDM) process. Experiments have been conducted using L16 orthogonal array with two different types of wire electrodes and by tuning following controllable process parameters; discharge current, flushing pressure, wire tension, and pulse-on time. It has been observed that zinc coated brass wire produces lesser kerf width as well as surface roughness; higher MRR as compared to brass wire electrode. The pulse-on time is found to be the most singnificant factor on influencing MRR for all electrodes types. Pulse-on time and discharge current is found to be very singnificant on affecting kerf width for all electrodes types finally, Grey-Taguchi relational analysis have been adopted to establish the optimal parametric combination for both the wire electrode.
Keywords: Material Removal Rate (MRR); kerf width; surface roughness; Inconel 718; Wire Electro Discharge Machining (WEDM); Grey-Taguchi.
Lin-Sontag and common Lyapunov functions for stabilizing control of a switched nonlinear systems
by Abdessmad Abdelhadi, Wided Saadi, Driss Boutat, Lassaad Sbita
Abstract: This work presents a control of switched nonlinear systems. The approach is based on stabilization by using control Lyapunov functions. A necessary and sufficient condition for stabilization, based on the existence of a common Lyapunov control function for switching subsystems, is presented in first time. Secondly, a stabilization control device is designed for non-linear switching system using the theory of common Lyapunov function and state feedback control of Lin-Sontag. Finally, this proposed approach is illustrated on the example of a switched reactor.
Keywords: Switched systems; Stabilization; Control; Lyapunov Functions; Reactor.
The influence of different quantity discounts on integrated supplier-retailer inventory model
by Yu-Jen Lin, Shwu-Huey Lin
Abstract: This paper investigates an integrated inventory model with defective items where the supplier will offer different quantity discounts to the retailer by different defective rate. We consider the supplier has to offer all-units quantity discount to retailer, as the retailer inspects the receiving items are too highly defective rate. Otherwise, the supplier offers price-break quantities discount to the retailer. Our objective is to determine the optimal order quantity of the retailer and the optimal number of shipment per production run from the supplier to the retailer, so that the joint total profit has a maximum value. An algorithm is developed to find the optimal solution. Two examples are provided to illustrate the theoretical results, and the management insight is presented to demonstrate from the numerical examples.
Keywords: integrated inventory system; quantity discount; defective items.
A robust possibilistic programming model for simultaneous decision of inventory lot-size, supplier selection and transportation mode selection
by Atousa Zarindast, Seyed Mohamad Seyed Hosseini, Mir Saman Pishvaee
Abstract: As a result of the uncertain changes in global currencies, exchange rates have become a critical part of suppliersselection problem.In the present paper the problem of supplier, transportation mode selection and inventory replenishment decision(STSI)in the presence of uncertain changes of currency exchange rates and price discounts have been studied. The present article addresses the STSI problem for a buyer sourcing a product from heterogeneous suppliers. Global suppliersselection procedure is based on the prices that suppliers offer in their local currencies.Late deliveries and rejections also exert influence on sourcing and inventory replenishment decisions. The proposed model is a bi-objective mathematical programming, objective functions of which are minimizing the total cost and the late delivery of items.In order to cope with uncertain parameters effectively, a robust possibilistic programming approach is utilized. Finally, to assess the robustness of the solutions obtained by the novel robust optimization model, our models results are compared to those generated by the chance-constrained programming model under the data of STAM SANAT Company. Further, the advantages of using this integrated approach versus a sequential approach under currency fluctuations are shown.
Keywords: Supplier selection; Lot-size; Transportation mode selection; Robust programming; Discount; Currency exchange rate uncertainty.
Operational behaviour of a clarifier system in the sugar industry using supplementary variable technique
by Ramesh Kumar, M.S. Kadyan
Abstract: In this paper, the clarifier system in the sugar industry is analysed that having three subsystems- Raw juice heater, Juice sulphitor and Sulphited juice heater. These subsystems are arranged in series. Both the subsystems Raw juice heater and Sulphited juice heater have standby unit whereas subsystem Juice sulphitor has single unit. The time to failure of the subsystems follows negative exponential distribution while repair time distribution is taken as arbitrary. The differential-difference equations associated with the state changeover model are developed by using supplementary variable technique and these equations are solved to get state probabilities of the system model. A particular case is also considered to show the behaviour of availability and expected profit of the clarifier system in the sugar industry.
Keywords: availability; clarifier system; expected profit; sugar industry; supplementary variable technique.
Performance Analysis of a FLP Problem using AHP-TOPSIS and FAHP-FTOPSIS
by Divya Agarwal
Abstract: To meet the ever-increasing demands of manufactured product and rising competition among rival industries; well-organized, inexpensive, efficient and effective facility layout plan (FLP) needs to be equipped. FLP decision problem entails to assignment of departments, positioning of machine equipments, material handling decisions, design as well as planning of production operations, required for higher productivity with better quality and improved efficiency. It is estimated that 70% of the total production cost is due to material handling (including equipments, direct-indirect labor costs, etc.), within a facility layout however, better facility placement can contribute to up to 30% less operating expenses. ABC Pvt. Limited was considered for FLP problem because of improper material flow through shop floor and extended transportation time for material transfer. The objective of this research is to analyze and compare the performance of existing Front Axle Division Layout of ABC Pvt. Limited with the four proposed design alternatives using AHP-TOPSIS and FAHP-FTOPSIS, thereby reducing production time, material handling distance and material handling cost (MHC). The management of the case study company has adopted the analysis results as the basis to their future layout planning problem. The practical contribution of this research can, thus, be justified.
Keywords: Facility Layout; Analytical Hierarchical Process (AHP);Fuzzy AHP (FAHP); Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS); Fuzzy TOPSIS (FTOPSIS); Material Handling; Multiple Criteria Decision Making Problem (MCDM).
The New Ranking method of the Decision Making Units in DEA: with an Approach to Modifying the Cross Efficiency method.
by Behzad Paryzad
Abstract: There is no doubt that organizations need an operation evaluation and measurement for having more efficiency and an optimal usage of their limited sources. One of the most practical methods for evaluating the operation is using the data envelopment analysis. Hence, DEA (Data Envelopment Analysis) and ranking DMU (Decision Making Units) are the most favorite subjects for the researchers. This method has modified on a different style on this article that has removed the existence of multiple optimal answers in the CCR (Chames-Cooper and Rhodes). In other words, the acquired ranks of the units are particular and have achieved with a special delicacy. In order to show the efficiencies of the method, some examples have presented that had achieved the more desirable and accurate ranking. The calculated results of performing this method have compared with the Anderson-Peterson method and its flexibility has studied according to the ANOVA (Analysis of Variance).
Keywords: Cross Efficiency; New ranking method; DEA; ANOVA.
A state-of-the-art literature survey of grey relational analysis(GRA)applications in competitive business environment
by Arvind Jayant, Vikrant Giri, Pradeep K. Singh, Sunil Luthra
Abstract: Multi-Criteria Decision Making (MCDM) approaches have been accepted a significant consideration from scientists and professionals for evaluating, surveying and selecting best alternatives for different commercial enterprises (production industries, e-commerce providers and many more). Out of various MCDM approaches developed to unravel real-world decision making problems, Grey Relational Analysis (GRA) keeps on working satisfactorily over diversified fields of business. In this paper, we conduct a state-of-the-art literature survey to taxonomize the research on GRA applications and methodologies in competitive business environment. The present paper is classified into five fields of applications viz. Supply chain and logistics management, manufacturing systems and design engineering, management and business, energy and environment management and some other areas of application. Research papers on GRA requisitions are again distributed based on number of publications in consecutive years and other methodologies compared or coordinated with GRA. We concluded our review paper with recommendations for future research directions in GRA decision-making that is both forward-looking and practically oriented. This paper provides useful insights into the GRA based decision making applications in the real business world and suggests a framework for future attempts in this area for academic researchers and industry practitioners. Keywords: Grey Relational Analysis (GRA), Supply Chain Management (SCM), Environment management, Multi-Criteria Decision Making (MCDM).
Keywords: Grey Relational Analysis (GRA); Supply Chain Management (SCM); Environment management; Multi-Criteria Decision Making (MCDM).
Cloud Based Manufacturing Execution System: Case Study FMS
by Ali Vatankhah Barenji
Abstract: In this paper, the needs and challenges confronted by the IT infrastructure of Small and Medium Sized enterprises (SMEs) was analyzed. The findings showed that the needs and challenges in data integration within the SMEs network affects the complexity of the IT system as well as the communication between the enterprise resource planning(ERP) and manufacturing execution system(MES), resulting in the lack of real time delivery. In other to cover the gaps between MES and ERP, this paper proposed a cloud based MES (CbMES); to develop the CbMES, a framework based on the model driven architecture (MDA) was used. This framework is a step-by-step framework for developing CbMES. For evaluating the proposed system, a flexible manufacturing system is selected as the case study. The proposed CbMES is developed for flexible manufacturing system and has been implemented within the oracle cloud platform, for the evaluation of this system, a simulation platform based on the color petri net is utilized. The result of simulation indicates that the proposed CbMAS is capable of closing the gaps between MES and ERP; therefore, the outcome of the results showed that the uptime productivity and the production rate of flexible manufacturing systems increased considerably meaning that the system is an effective and viable solution for the IT infrastructure.
Keywords: ERP; MES; Model Driven Architecture; Software as a Service; Cloud Computing.
Risk Assessment Modelling for Power Optical Backbone Communication Network based on MLFSR-oriented Sampling Markov Technique
by Huisheng Gao, Yujun He
Abstract: Considering the large-scale power optical backbone communication network with diverse link failure statuses and complicated service configuration modes, a hybrid multi-link failure statuses reduction (MLFSR)-oriented Sampling Markov technique used for network service risk assessment is proposed. First, the multi-link failure events, statuses and Markov model have been introduced for power communication network. Second, the link failure probability p is determined through link failure rate λ and repair rate μ. Then the link failure statuses can be reduced according to p, links number n and confidence level α;, which simplifies the failure state Markov model with less calculation work in assessing the possible service loss. Third, for certain reduced valid link failure status, there are also a large number of failure events. Considering the sampling accuracy, the sample size (i.e. failure events) for each link failure status can be further reduced based on t bilateral percentile statistic theory, resulting in less calculation in service loss estimation. Finally, the concrete risk assessment procedures of the proposed method are described, and the simulation and comparison analysis are carried out for a practical communication network to test the feasibility and validity of the proposed method. The results show that the network risk R has approximate linear relationship with the link failure rate λ and the mean repair time τ. This study is expected to be of significant reference value for formulating risk-controlling measures to diminish communication network risk for operation departments.
Keywords: power communication network; optical backbone network; link failure status reduction; service risk.
A Multi-objective Programming Model for Selection Third-Party Logistics Companies and Suppliers in a Closed-loop Supply Chain
by Hashem Omrani, Iman Hushyar, Saman Moradi Zolmabadi, Abolfazl Jafari Asl
Abstract: Due to globalization and increasing competition in markets, the manufacturers and service organizations tend to outsource their logistics activities. On behalf of manufacturers and service organizations, an outer firm which called third party logistics (3PLs) company manages, controls and performs the logistics activities. In this paper, a general closed-loop supply chain network is designed that includes manufacturers, third party logistics (3PLs), supplier, evaluation, disassembly, refurbishing and disposal sites. The proposed model of this paper has two phases. First phase determines 3PL and external supplier by using fuzzy sets theory. Namely, the preferences of decision makers for selecting 3PLs and suppliers are expressed by triangular fuzzy numbers and then, the weights of 3PLs and suppliers are determined. In the second phase, a multi-objective mixed integer linear programming model is proposed to determine the product optimum quantity assigned to the 3PL and parts purchased from supplier. The proposed model considers 3PL and supplier selection, simultaneously. To illustrate the capability of the suggested model, a numerical example is solved and the results are analyzed.
Keywords: Supply chain management; Reverse logistic; Suppliers selection; Third party logistic (3PL); Mixed integer linear programming; Fuzzy logic.
Investigating the application of meta-heuristic algorithms in optimizing opportunistic maintenance: an exploratory study
by Arash Shahin, Saeede Jokar
Abstract: Opportunistic maintenance is very effective in optimizing the existing costs of production. The aim of this article is to optimize opportunistic maintenance. For this purpose, based on an example, various methods such as genetic algorithm, imperialist competition algorithm, simulated annealing algorithm, artificial bee colony algorithm and particle swarm algorithm have been considered for solving the problem and the approaches have been compared to find the most cost effective approach. Findings imply that the imperialist competition algorithm is the most suitable solution.
Keywords: Opportunistic Maintenance; Optimization; Imperialist Competition Algorithm; Simulated Annealing Algorithm; Genetic Algorithm; Artificial Bees Colony Algorithm; Particle Swarm Algorithm.
Analysis on the characteristics for a new differential crawling device of an insulator inspection robot
by Xiaopeng Li, Wujiu Pan, Shujun Li, Hongguang Wang
Abstract: In order to realize the synchronous drive of the insulator inspection robot with a simple control system, a single drive crawling device of the robot is designed. This device has a three-degree freedom (3-DOF) differential drive system which can be driven by a motor to make the three sets of arm crawl synchronously. It has a certain ability of self-adaption and compensating output errors. First, the crawling devices assembly model of insulator inspection robot is designed which includes three main components：crawling arms, driving mechanism and guiding mechanism. Then the kinematics analysis is established. In addition, a kineto-statics model is founded to analyse the total torque and the stress state of the contact points when the device is crawling. Finally, simulation is used to analyse and the error adjustment of crawling device is studied. After theoretical analysis and dynamic simulation of the crawling device, results show that it has a certain ability of error adjustment and will run normally when there is an oblique angle error with the suspension insulator strings.
Keywords: insulator; inspection robot; differential drive; crawling device; error self-adjustment.
Robust Integral Backstepping Control with Extended Kalman Filter of Permanent Magnet Synchronous Motor
by Bassema Bakhti
Abstract: Sensorless integral Backstepping control combined with Extended Kalman Filter applied to permanent magnet synchronous motors (PMSM) is the topic of this paper. Moreover, a robust Backstepping control is designed where an integral action is introduced in order to improve the robust properties of the controller.Our proposed control strategy is based on an accurate extended Kalman filter observer that estimates speed, position, stator currents and load torque. This Kalman filter is an optimal state estimator and is usually applied to a dynamic system that involves a random noise environment. The stability of the system with the observer controller scheme is analyzed and sufficient conditions are given to prove the practical stability. Simulation results are shown to illustrate the performance of the proposed scheme under parametric uncertainties and low speed.
Keywords: Permanent magnet synchronous motor; PMSM; Sensorless control; integral Backstepping control;I-Back; Extended Kalman filter; EKF.
Exploring the Relationship of Discrete Components of Inventory with Financial Performance in Indian Automotive Industry
by Tanuj Nandan, Vikas Kumar Choubey
Abstract: Inventory holdings and its discrete components [i.e. Raw Materials Inventory (RMI), Work in Process Inventory (WIPI) and Finished Goods Inventory (FGI)] are very important factors influencing the firm performance. The objective of this paper is to study the relationship between discrete components of inventory (raw material (RM), work-in-process (WIP), and finished goods (FG)), and financial performance in manufacturing companies. Statistical analysis has been applied to the financial information of 522 Indian automotive manufacturing firms over the 10-year period from 2002-03 to 2011-12. Through the analysis, this paper finds statistically significant relationships between the discrete components of inventory and measures of financial performance (at both the gross and operating levels) for firms in automotive manufacturing industries. This paper adds to previous literature by discussing and testing the relationship between the discrete types of inventory (RMI, WIPI, and FGI) and firms profitability of operations, both at the gross and at the operating profit levels.
Keywords: Discrete components of Inventory; Financial performance; Operational efficiency; Automotive manufacturing industries.
Statistical Study on the use of the measurement techniques in predictive maintenance taking Moroccan companies as an example
by Amal BOUKILI, Mohammed EL HAMMOUMI, Said HAOUACHE
Abstract: This article presents where Moroccan companies stand the use of the measurement techniques in predictive maintenance. The objective is to identify the main advantages and disadvantages of each measurement technique (vibratory analysis; thermography; radiography; penetrant testing; magnetoscopy and ultrasonic) taking into account the characteristics of the production (continuous, discontinuous, by project) and the sector of activity (agri-food, automobile, textile, service sector...).
This survey allows determining how many Moroccan industries use measurement techniques to avoid breakage that could slow down and even stop producing a preventive maintenance program.
It brings the original data on the choice of a technique among others considering the nature of the physical monitoring parameter and criteria of speed, cost, reproducibility, reliability, sensitivity and resolution of each measurement technique.
As a result, the industrial managers may rely on the results of this survey in order to use a maintenance program directed to a predictive maintenance. The most suitable technique should be chosen, taking into consideration the field of activity of each company and based on the advantages and disadvantages of each measurement technique.
Keywords: preventive maintenance; vibratory analysis; thermography; radiography; penetrant testing; magnetoscopy and ultrasonic; speed; cost; reproducibility; reliability; sensitivity and resolution.
Assessing Software Upgradation Attributes & Optimal Release Planning Using DEMATEL & MAUT
by Rana Majumdar, P.K. Kapur, Sunil.K. Khatri
Abstract: This study analyzes the software upgradations aspects of industries by applying the Decision Making Trial and Evaluation Laboratory (DEMATEL) method and then finding the Optimal Release Time of the Upgraded software using Multi Attribute Utility Theory (MAUT) to remain competitive in the market. The software developers are trying very hard to mark their presence by offering new functionalities in the software within defined time frame. Founded on the literature reviews and based on experts opinion, three significant viewpoints and eight attribute were identified as Key factors and then further confirmed by industry professionals. In the process of confirmation/validation a survey was conducted, professionals expressed their views based on questionnaires. DEMATEL method used for attribute analysis and finally casual relations among the attribute were shaped. The result exhibited that the strategic perception from management point of view was the most significant perception and greatly influenced the remaining two viewpoints. The applicability of DEMATEL method is to confirm interrelationships among diverse attributes and helps to recognize the key attributes whereas the role of MAUT process is to identify the release time of Software based on casual relations among attributes. This work orients itself by identifying different attributes for software upgradations and then related attributes are listed under key viewpoints. The causal model identifies the main causes and effects and also specifies priorities of each attributes. By using the influenced-influencing matrix, key factors were identified. We examined the proposed technique on primary data collected from IT companies and obtained significant results that provides for far greater insights into upgradation attributes than existing processes. During the process of applying DEMATEL & MAUT, panel of experts plays a balancing and support role for software upgradations and release time planning. So here the objective is twofold. i) To identify and analyze upgradation attributes ii) Based on analysis/outcome of DEMATEL method optimal release time of software is determined
Keywords: Decision Making Trial and Evaluation Laboratory; Cause and effect relationship; Multi Attribute Utility Theory.
Reliability Evaluation and Improvement of Manufacturing Helicopter in an Aircraft Manufacturing Company Case Study: Skid Types Helicopter Landing Gear
by Mohammad Farahmand, Maliheh Ganji, Seyed Mojtaba Sajadi
Abstract: Due to its sensitivity to time and accuracy, aerospace equipment requires a highly accurate manufacturing process to achieve higher reliability compared to other equipment. Focusing the studied helicopter, this study examines reliability of components of a landing gear manufactured by an aircraft company to improve total reliability of the product. Developing a model for risk-based design of a landing gear, this study proposes an inclusive approach for evaluating and promoting total reliability of the landing gear. This study identifies different components of a product to examine reliability of a component of that product. Then, the components are prioritized by FMEA for promotion to increase total reliability of the product. In conclusion, the objective of this study is to develop an inclusive model for improving reliability of mechanical components of landing gear manufactured by an aircraft company.
Keywords: Reliability;Feasibility of Objectives (FOO); Fault Tree Analysis (FTA); Failure Modes and Effects Analysis (FMEA); Helicopter Landing Gear.
One vendor and multiple retailers system in vendor managed inventory problem with stochastic demand
by Cahyono Sigit Pramudyo, Huynh Trung Luong
Abstract: In many supply networks, the retailers are reluctant to share information about demand and inventory level to the vendor. This might lead to many difficulties for the vendor in establishing his own order/production plan. Vendor managed inventory (VMI) policy can help to solve that problem. By applying VMI, information sharing is not really a problem for the vendor anymore and this policy have been proven to help reduce total inventory cost as well as improve customer service level in the supply network. In this research, a VMI model for the system with one vendor and multiple retailers will be developed. The main target of the model is to determine the retailers lot size, the vendors lot size, the retailer cycle time, and the number of replenishments in a vendor cycle so as to minimize the total system cost. For solution purpose, simulation-optimization technique using genetic algorithm is employed to help find optimal solutions for the decision variables. Numerical experiments are conducted to show the applicability of the proposed model. Sensitivity analysis is also conducted to examine the effects of some input parameters on the optimal solution.
Keywords: Vendor managed inventory; genetic algorithm; stochastic demand.
Improving Dual Importance Analysis Based on A Shapley Value Associated with A Fuzzy Measure When Interactions of Criteria are Significant
by Jiunn-I Shieh, Hsin-Hung Wu
Abstract: Kano model is very useful to classify customer needs into different categories by completely using self-stated evaluations. The disadvantages of using self-stated evaluation are respondents often find it difficult to differentiate and respondents answers may be influenced by social norms or political correctness. In contrast, the derived evaluation approach uses a less direct way of uncovering the evaluations that are most reliable to reflect the respondents view from the survey. Multiple regression, structural equation modeling, partial correlation, or generalized correlations commonly used in the derived importance are all based on weak interaction assumption among items. However, an interaction effect particularly non-linear interaction is often incurred in practice. To overcome this major drawback, a framework of using the dual importance graph with self-stated performance and derived importance to classify the service items into different types of Kanos categories is proposed. The derived importance was computed by a Shapley value associated with a fuzzy measure method to deal with significant interactions among items by further considering both linear and non-linear effects instead of solely considering and assuming linear effects. A case of evaluating the service quality of a particular hospital is illustrated to show how this proposed framework works to classify the service items into different types of Kanos categories. The result shows that using the Shapley value-based dual importance graph is more practical to deal with interactions of items.
Keywords: Kano’s model; dual importance diagram; Shannon interaction information; fuzzy measure; Shapley value.
An integrated analytical framework based on fuzzy DEMATEL and fuzzy ANP for competitive market strategy selection
by Mohamad H. Gholami
Abstract: Selection of an appropriate competitive market strategy is inevitable for firms to create value for customers and consequently to achieve competitive advantage over their competitors. However, selection of such strategy is not straightforward at all because it requires considering numerous factors including internal and external factors that affect the firms performance and assessing the complex relationships between them. The current study considers the selection of the best competitive market strategy as a multiple criteria decision making problem and proposes an integrated framework on the basis of the resource-based view (RBV) of the firm as internal factors (firm-level analysis) and Porters competitive forces as external factors (industry-level analysis). The aim of the current study is to propose a systematic decision support framework integrating the RBV of the firm and Porters industry analysis to select the best competitive market strategy that can enhance the competitive advantage of a firm. The suggested framework utilizes fuzzy decision making trial and evaluation laboratory (fuzzy DEMATEL) and fuzzy analytic network process (fuzzy ANP) in both firm-level and industry-level analyses to obtain the causal relationships between criteria and to solve the networks, respectively. Also, the discussion on how to provide a settlement between the two analyses is presented. Furthermore, to demonstrate the application of the developed framework, an empirical example from insurance industry is provided.
Keywords: Competitive market strategy; Resource-based view (RBV); Porter’s competitive forces; Porter’s generic strategies; Fuzzy decision making trial and evaluation laboratory (fuzzy DEMATEL); Fuzzy analytic network process (fuzzy ANP).
A multi-objective modeling approach to assess the impact of maintenance scheduling on equipment procurement methods
by Ali Sayyah, Reza Baradaran Kazemzadeh, Mohammad Mehdi Sepehri, Hamidreza Eskandari
Abstract: In this research, a new multi-objective optimization model is developed from equipment users point of view who is seeking to select from among the buy/lease/upgrade decisions and maintenance schedule options when the equipment performance criteria and total cost are in consideration. The proposed model determines the possible non-dominated physical asset management (AM) strategies by interconnecting procurement parameters, maintenance scheduling variables, and equipments working historical data. Total operational cost, the equipment reliability and unavailability are the objectives of the model which is solved using NSGA-II. Each of the achieved strategies consists of a procurement method (buy/lease/upgrade) and a maintenance strategy (PM degree, PM interval and upgrade level). The model is applied to a specific equipment to determine non-dominated asset management strategies for a specified time horizon in a copper mine. The results show that by managing maintenance variables, the decision maker is capable of choosing a proper procurement strategy to the organization from among various equivalent AM strategies.
Keywords: Maintenance Scheduling; Multi-objective Optimization; Equipment Procurement; Physical Asset Management; Reliability; Unavailability; NSGA-II.
A Resilient Supply Portfolio Considering Political and Disruption Risks
by Reza Hosnavi, Mohammad Ali Nekooie, Seyed Mohammad Khalili, Ahmad Tavakoli
Abstract: The need of accounting for resilience in global supply chains has been growing from practical and academic points of view. However, there is still the need for developing quantitative decision support models on this issue. In the present work we propose a novel multi-objective mixed possibilistic, two-stage scenario-based stochastic programming model to handle supplier selection and order allocation problem in a global supply chain under operational and disruption risks. The model minimizes cost and political risk, whilst, maximizes resilience of the supply portfolio. Various risk mitigation approaches including: contracting with backup suppliers, fortification of suppliers and procurement of emergency inventory, are considered in the model. In addition, the proposed model determines recovery plan. Reservation Level driven Tchebycheff Procedure is incorporated in the solution procedure to find Pareto-optimal solutions. The validation of the model via computational experiments demonstrate the applicability of the proposed model and solution method in building a resilient supply portfolio under consideration of operational and disruption risks.
Keywords: supply chain risk/disruption management; resilient supply portfolio; mixed possibilistic two-stage stochastic programming.
Quality Management Practices and Sustainable Performance: Examining the Role of Soft TQM as Mediator
by Amjad Khalili, Md Yusof Ismail, A.N.Mustafizul Karim, Mohd Radzi Che Daud
Abstract: Malaysian managers are trying to implement Quality Management (QM) practices in their industries to be competitive. However, minute empirical studies are conducted in the developing economy of Malaysia to examine the role of TQM soft dimension (STQM) as possible mediator in the relationship among QMS ISO 9001:2015 and Sustainable Performance (SP). Exhausting 329 primary data collected from Malaysian numerous industries; this paper aims to develop a conceptual model that links the three practices namely QMS, STQM and SP in one integrated model and to examine the mediating structure of Soft TQM (STQM) aspects through techniques exploited from Structural Equation Modeling (SEM). Findings from AMOS program show that Bootstrapping technique supported that STQM is treated as mediator construct. Though, full mediation is detected in this paper which reflects the importance of practicing STQM aspects for Malaysian manufacturers. The main contribution of this paper is through introducing bootstrapping for mediating estimation and focusing on all measured industrial sector in Malaysia needs to be an industrialized nation in the coming few years.
Keywords: QMS; Soft TQM; Sustainable; Mediating; Bootstrapping; Malaysia.
Analysing Salesmen Itinerary with Agglomerative Hierarchical Clustering & Vehicle Routing Algorithm - a case study of a confectionery supplier in Indonesia
by Elia Oey, M. Idham Sofyan, Alexander Batara Marpaung
Abstract: The study analysed salesmen itinerary of a confectionery supplier in Indonesia. Channel management and robust product distribution are important elements for confectionery business, since growth heavily depends on healthy product distribution. To support product distribution, optimizing salesmen itinerary plays an important role in the firms sales operation. The study was limited to optimizing salesmen schedule for its wholesalers outlet type, since it contributed to 78% of its revenue. The analyses were carried out using cluster first-route second approach. For clustering the customer nodes, it recommended agglomerative hierarchical clustering (AHC) method. For routing within each customers cluster, it tested two algorithms, i.e. Clarke-Wright and Weighted-Serving Time-Visual approach. The result showed that AHC-Weighted-Serving-Time-Visual algorithm was as good as AHC-Clarke-Wright with 2.1% cheaper variable cost. The proposed algorithm was adapted from practical insight and easier to be understood.
Keywords: Cluster first-route second; Vehicle Routing Problem (VRP); Agglomerative Hierarchical Clustering (AHC); Clarke-Wright; Weighted-Serving Time-Visual approach.
Managing Cost of Quality in Supply Chain: A Case Study
by Amiya Pattanayak, Anand Prakash, Rajendra Mohanty
Abstract: This paper attempts to present the overseeing situation of cost of quality (CoQ) in the supply chain of an integrated aluminium manufacturing company as the case example shown by the authors. The study has critiqued a wide range of published literature to provide an indepth review of CoQ and CoQ in the supply chain. This study describes an application of grounded theory approach for CoQ in the supply chain to demonstrate what can be found and how the information on CoQ in supply chain of the case example can help. The study considers rigorous methodological usefulness of the research results to benefit researchers and practitioners in making financial improvements, with justification in planning and controlling of quality in the supply chain. This study explains that CoQ in the supply chain helps in realising there is a sustainable competitive advantage through its proficient know-how advancement founded on internal analysis under conditions of uncertainty, complexity and conflicts.
Keywords: Cost of Quality; Grounded Theory; Management; Quality; Quality Cost; Supply Chain.
Evaluation of reliability, availability and maintainability of a milk production line
by Panagiotis Tsarouhas
Abstract: The application of statistical approaches of failure data for analyzing the reliability, availability and maintainability of a milk production line were carried out. Descriptive statistics of the failure and repair data was computed and the best fitness indexes were determined. The parameters of some idealized probability distributions, such as Weibull, Exponential, Lognormal, and normal distributions have been estimated. Reliability and maintainability (R&M) of workstation and the entire line at different mission times with their best fit distribution have been estimated. Both R&M proved to be useful tools to assess the current situation, and to predict reliability, mainly in short term, for upgrading the operation management of the milk production line. It was pointed out that: (a) the availability for the milk production line was 96.13% and the line was down or under repair for 3.9%. (b) Both bottling machine and heat exchanger/pasteurizer machine had 57.5% of all the failures that presented on the production line, and (c) there were no-trend and serial correlation for both failure and repair data. The records of failures and repairs can be a useful database for manufacturers of milk industry to design new reliable and safe equipment.
Keywords: Reliability; maintainability; performance evaluation; field failure/repair data.
An Integrated AHPDEA methodology for Evaluation and Ranking of Production Methods in Industrial Environments
by Saeideh Naghiha, Reza Maddahi, Ali Ebrahimnejad
Abstract: Decision making about the superior method to produce products is essential to growth and dynamism of productive organizations. In this regard, utilizing a model to evaluate the comprehensive performance of different manufacturing methods is significant. In addition, defining and finding the suitable indexes of decision making is required to the proper implementation of performance evaluation system. Thus, in this study, it is attempted to select the best production method and to supply material using Data Envelopment Analysis (DEA) technique and analytic hierarchy process (AHP). In this regard, the performance of Ball valve production in Petro Nab Sepahan Manufacturing Company is assessed and ranked using these two methods by considering dimensions such as quality, cost, and function as well as acquired measures.
Keywords: Performance assessment; Efficiency; Analytic hierarchy process (AHP); Data Envelopment Analysis (DEA); Ball valve.
Warranty Cost Sharing Policies with Preventive Maintenance Strategy for Sensor Embedded Remanufactured Products
by Ammar Alqahtani, Surendra Gupta
Abstract: With the recent surge of technological development and consumer preference to purchase newer device models and technological products, product life cycles have diminished and disposal rates have spiked. As a result, landfills and the Earths natural resources have begun to reach a critical apex. In response to this apex, when a technological device reaches the end of its life cycle, and it becomes obsolete, manufacturing firms now repossess the products they produced. Manufacturers attempt to respond to consumers concerns involving environmental issues as well as the more governmentally stringent environmental legislations by establishing facilities which include the minimization of the totality of waste relocated to landfills by recovering materials and components from returned, or End-Of-Life (EOL) products and reuse them to build a remanufactured product, and/or novel components. With the rapid growth of interest in remanufactured products market, offering warranty for remanufactured products and components is becoming a necessity for remanufacturer in order to meet customers requirement and as a marketing mechanism. During that process, maintenance policies are of great importance in order to reduce the warranty cost on the remanufacturer. In this paper, an optimization simulation model for remanufactured items sold with one-dimensional non-renewing Cost Sharing Warranty (CSW) and Cost Limit Warranty (CLW) are proposed from the view of remanufacturer. In which, an End-Of-Life product (EOLP) is subjected to upgrade action at the end of its past life and during the warranty period, preventive maintenance actions are carried out when the remaining life of the product reaches a pre-specified value so that the remanufacturers expected profit can be maximized. Finally, a numerical example and Design of Experiment analysis are provided to demonstrate the proposed approach.
Keywords: Reverse Supply Chain; Preventive Maintenance; Warranty Policies; Remanufacturing; Sensor Embedded Products.
A precise direct parametric interpolation method for NURBS-toolpath generation
by De-ning Song, Zhen-yuan Jia, Jian-wei Ma, Ning Zhang, Li-kun Si
Abstract: Non-uniform rational B-spline (NURBS) interpolator has many advantages over conventional linear/circular interpolator. However, as there is a nonlinear corresponding relation between the curve parameter and the arc displacement of the NURBS curve, it is hard to accurately calculate the parameter of the next interpolation point, thus resulting in a deviation between the desired and the actual feedrate, i.e. feedrate fluctuation. A large feedrate fluctuation may cause the machine-tool vibration, which is bad for the cutter life and the machining quality. Therefore, aiming at reducing the feedrate fluctuation, this paper presents a high-precision parametric interpolation method, which features a second-order Runge-Kutta algorithm with parameter compensation. First, a second-order Runge-Kutta method is employed to compute the initial interpolation-point parameter. After that, the parameter is compensated using first-order Taylors expansion of the feedrate-fluctuation function, thus enhancing the calculation precision of the next-interpolation-point parameter. Experimental results demonstrate the advantage of the presented method.
Keywords: Parametric interpolation; NURBS interpolator; Feedrate fluctuation; High-precision machining.
An active observer based predictive energy management strategy for engine waste heat recovery system
by Zhengling Lei, Hui Xie
Abstract: In this paper, energy management of waste heat recovery system has been attacked based on a three-steps problem formulation approach. The problem has been formulated into a bilevel programme, where the upper level is designed to optimise the usage of recovered energy and the lower level is arranged to maximise the recovered energy. However, detailed models for real-time decision-making cannot be easily obtained. In order to ensure the energy management performance, an active observer named extended state observer is adopted to compensate for static models via online information of the real energy network. The final decision-making of the energy management is conducted based on the reconstructed model, which is simpler and more accurate. An energy network constructed by -----is employed as the research object. Simulation study conducted by GT-SUITE software is used to verify the sub-goals of the problem configuration, including model self-reconstruction capability and fuel-saving potential. For two given testing cycles, simulation results indicate fairly good self-reconstruction capability can be ensured, while considerable fuel-saving capability can be reached comparing with a baseline strategy, indicating the effectiveness of the proposed approach.
Keywords: engine waste heat recovery; extended state observer; bilevel programming; energy management.
Simulated annealing algorithms to minimize the completion time variance of jobs in permutation flowshops
by J. Krishnaraj, S. Pugazhendhi, Chandrasekharan Rajendran, S. Thiagarajan
Abstract: In this paper, the permutation flowshop scheduling problem with the objective of minimizing the completion time variance (CTV) of jobs is considered, and a simulated annealing algorithm (SA) and two modified SAs (MSA1 and MSA2) are proposed. In the first phase, the proposed algorithms are used to minimize CTV of jobs without any right shifting of completion times of jobs on the last machine (RSCT). As followed in the literature some times, the RSCT (except that of the last job) is attempted in the second phase, and in the third phase, we convert sequences so as to follow the V-shaped property with respect to processing time of jobs on the last machine, followed by RSCT except that of the last job, so that the makespan and the machine utilization in the shop floor remain the same. We present an extensive computational evaluation of the existing and the proposed heuristic algorithms.
Keywords: Scheduling; Permutation flowshop; Simulated annealing algorithm; Completion time variance.
An Application of Routing Location and Allocation Model for Drinking Water Distribution
by Armagan Bayram, Senay Solak
Abstract: Due to severe droughts occurring in southwest China, this region is facing a perilous water crisis for a long time. To meet the daily drinking water demand, the government is sending water to these rural areas via trucks. This study addresses a type of vehicle routing problem motivated by a drinking water distribution application (via trucks) in Luxi County, China to help alleviate the drought in this region. A specific characteristic of this application is that the vehicle routing problem is integrated with facility location and allocation problems. We model this problem as a mixed-integer program where the objective involves the minimization of a weighted function of efficiency (i.e. vehicle transportation costs) and equity (i.e. village assignment costs) metrics. Due to the computational complexity of the integer programming model, two heuristic approaches are proposed to obtain more efficient and practical solutions. Through our heuristics, we split the problem into the routing and location-allocation models and solve them sequentially. We further propose Benders decomposition algorithm and perform computational analysis to compare the efficiency of mixed integer programming model, heuristic approaches and Benders decomposition algorithm by using realistically generated instances. Through our computational analysis, we also explore how different objective metrics influence the distribution of drinking water.
Keywords: Vehicle routing and allocation; nonprofit vehicle routing; mixed-integer programming; resource allocation; water distribution.
A robust optimization model for sustainable blood supply chain network design under uncertainty
by Zahra Mohammadian, Armin Jabbarzadeh, Mir Saman Pishvaee
Abstract: Blood is a perishable, scarce and lifesaving product. While the demand for blood products has been increased over the past few decades, there has been no specified artificial alternative for this critical product yet. In this context, it is of paramount importance to design efficient, agile and effective blood supply chain networks. This paper presents a multi-objective stochastic programming model for blood supply chain network design by considering the following objectives: minimizing total cost, minimizing delivery time, and maximizing two important social measures including the indicator of consumers health and the rate of regular blood donors. A robust optimization approach is employed to incorporate different sources of uncertainties in demand and supply parameters. To investigate the performance and utility of the proposed formulation, the model is implemented using real data of blood transfusion network of Tehran.
Keywords: Blood supply chain; Network design; Sustainability; Uncertainty; ɛ-constraint method.
Experimentation and Weld Parameter Optimization using Grey Fuzzy analysis
by Satheesh Moni, Edwin John
Abstract: The most popular steel grade material highly used in the fabrication of industrial pressure vessels and boilers is SA516 Grade 70. Submerged Arc Welding is a metal joining technique widely used in heavy fabrication industries for its high quality, reliability, attaining deeper penetration and a smooth appearance of weld bead. In this paper, Taguchis L27 orthogonal array is used to perform welding of SA 516 grade 70 steel plates. To improve the weld quality, the optimal combination of welding parameters is chosen using grey relational analysis. Grey fuzzy optimization of welding parameters is based on four different output performance characteristics, namely, bead reinforcement, bead width, bead penetration and dilution. From Analysis of variance it is evident that electrode stickout is the most influential factor in submerged arc welding process parameters. Mechanical and metallurgical studies are performed to confirm the effectiveness of the approach.
Keywords: ANOVA; Bead geometry; Orthogonal array; Taguchi method;Fuzzy.
Analysis of Machine-Repairing Systems with Server Breakdown and Delayed Repairs
by Jau-Chuan Ke, Tzu-Hsin Liu, Ying-Lin Hsu, Hui-Tzu Ku
Abstract: This paper considers a machine-repairing system with a partial breakdown and delay-repairs. When the servers fail, the service continues at a slower rate instead of stopping completely. We utilize a matrix-analytic method to obtain steady-state solutions. We then develop system performance measures. A cost model is developed to simultaneously determine the optimal value of the number of servers, the number of standby servers, the two service rates, and the cost of maintaining system availability at an acceptable level. We employ the probabilistic global search Lausanne method to deal with the optimization problem. Sensitivity analysis is also conducted in which various system parameters are evaluated under optimal operating conditions. Finally, an application example is provided to demonstrate how the presented model could be used in real-life situations.
Keywords: cost analysis; partial breakdowns; delayed repairs; warm standby machine; probabilistic global search Lausanne.
Reducing Barriers to the Implementation of Strategic Management by Providing Improved Strategies: Using Fuzzy QFD applied to Petropars Company
by Daryosh Mohamadijanaki, Abolfazl Mirzazadeh, Mehdi Mohamadijanaki
Abstract: In all organizations, the transition from strategy development to strategy implementation requires a change in responsibilities. Petropars has been chosen as a real case in the oil and gas industry. In this research, we have tried to address the fundamental problems of private companies in implementing strategic management, And in interviews with the top managers and experts of Petro Pars Company, some of the main barriers to implementation of strategic management were identified. In this paper, a quality-performance-based approach is proposed. Using the fuzzy method, different parts of the house of quality, and the relationship of the stakeholders' desire to improve barriers, are removed from linguistic and ambiguous strategies with strategic actions, How to use both the house of quality (HOQ) and fuzzy logic, and adding four new fuzzy parts to the quality house, and finally, using the quality home, the transformation of barriers to implementing strategic management to the improvement strategies is presented in Table 12.
Keywords: Fuzzy QFD; strategic management Obstacles; Petropars ,stakeholders.
Research on Static Friction Coefficient of Joint Surfaces Considering Elastic-plastic Deformation Based on Fractal Model
by Xiaopeng Li, Ze Wang
Abstract: In order to study the influence of the microscopic morphology on joint surfaces, it is necessary to consider the elastic-plastic deformation of micro-bulge. Based on the M-B fractal model, the mathematical equation of normal and tangential load of elastic-plastic deformation is obtained. Then, contact fractal models of static friction coefficient with the elastic-plastic deformation considered and not considered are established respectively. Two models have geometric characteristics and scale independence. The contact fractal model of static friction coefficient considering elastic-plastic deformation is analyzed by changing different characteristic parameters. And the nonlinear relationships between static friction coefficient and characteristic parameters of joint surfaces are revealed. The results show that the static friction coefficient is increased with the normal load and material parameters increase. While the static friction coefficient is decreased with the fractal scale parameters increase. And the relationship between the static friction coefficient and fractal dimensions is complex. When 1.1 Keywords: joint surfaces; elastic-plastic deformation; static friction coefficient; fractal theory; the nonlinear relationships.
Effect of individual and work parameters on musculoskeletal health of manual agriculture workers
by R. Jain
Abstract: Musculoskeletal disorders (MSDs) are a major work-related issue for farmers. The aim of this cross-sectional study to find out the occurrence and risk factors for MSDs in the manual agriculture workers. A sample of Indian workers was surveyed (N = 138). An information theory method was investigated to determine the comparative feature of mathematical models for a specified group of data collected on MSDs, individual and work parameters. The result from the AIC analysis used further to select a model of the extreme fit. Risk Factors associated with MSDs in the final model with 95% bootstrap contained age (40.5%), gender (24.5%), education (5.2%), income satisfaction (10.6%), tool satisfaction (8.4%) and smoking (10.8%). Problem attentions to MSDs are identical in developed and newly industrialized countries. However, factors are not exact similar. Interventions targeted at manual activities for degrading risk factors that furnish to MSDs are necessary.
Keywords: Agricultural systems; Information theory; Musculoskeletal disorders; Manual working; Marginal farmers; R statistical software.
Two-sided assembly line car sequencing with a fuzzy adaptive extended coincidence algorithm
by Parames Chutima, Watcharawit Tanontong
Abstract: The car sequencing problem is a constraint satisfaction problem that has attracted the attention of academia and practitioners for many years now. In this paper, the industrial version of the car sequencing problem is extended to reflect more real operations in practice by using a two-sided assembly line instead of classical single-sided one. The fuzzy adaptive extended coincidence algorithm (COIN-F) is developed to optimise the multi-objective car sequencing problem in a Pareto sense. The relative performance of COIN-F is compared against COIN-E, NSGA-II and DPSO. Experimental results demonstrate the effectiveness of COIN-F over the contestant algorithms, especially in the search for the approximate true-Pareto frontier.
Keywords: Car sequencing; two-sided assembly line; COIN; fuzzy adaptive.
A novel kind of electro-hydraulic loading system based on friction for actuator test
by Chenghu Jing, Hongguang Xu
Abstract: Conventional electric or electrohydraulic load simulator is disturbed by the motion of the tested system. To eliminate the strong motion disturbance and improve loading performance, a novel kind of friction electrohydraulic loading system is proposed. The mechanism of friction electrohydraulic loading system is described in detail. The math model for the loading torque and the input signal has been deduced, which indicates that this proposed friction electrohydraulic loading system has no disturbances resulting from tested actuators under ideal conditions. However, friction coefficient is time-varying and uncertain. The friction device increases the load inertia of the actuator. The additional inertia may affect the loading performance. The structure mechanism has been optimized to reduce the rotary inertia. To verify the loading performance of friction electrohydraulic loading system, simulations and experiments are carried out. Compared with conventional electrohydraulic load simulator, the theoretical analysis and experimental results validate the feasibility of the friction electrohydraulic loading method. The novel friction electrohydraulic load simulator, with a simple control principle and easy engineering constructability, can provide accurate torque simulation for actuator test.
Keywords: Electrohydraulic system; load simulator; loading system; motion disturbance; extraneous torque; actuator test.
Integrated supplier-buyer cooperative models with price-dependent demand and process quality improvement under two-part trade credit policy
by Hsien-Jen Lin
Abstract: This paper deals with an integrated supplier-buyer inventory model with process quality improvement where market demand is sensitive to the retail price and the supplier adopts two-part trade credit policy. The model has some insights in order to obtain optimal strategy of a business firm. The objectives of this paper are twofold. Firstly, we want to correct and improve the recently studied model by simultaneously optimizing order quantity, defective rate, retail price, and number of shipments from the supplier to the buyer to maximize the joint total profit. Secondly, we consider that the demand rate is retail price dependent and the production rate is finite and proportional to the demand rate to fit the real-life situations. For the proposed model, a computational algorithm is proposed for determining the optimal solution. Furthermore, numerical examples are provided to illustrate the modeling idea and effectiveness of the algorithm. Sensitivity analysis is conducted and some managerial implications are presented.
Keywords: integrated inventory model; two-part trade credit; price elasticity; quality improvement; capital investment.
Modeling the Problem of Yard Crane Deployment for Resource-limited Container Terminal
by Caimao Tan, Junliang He, Hang Yu
Abstract: With the bottleneck of container port has moved from the quay side to the yard area, the operational efficiency of yard crane is becoming increasingly significant to the container terminal. This article studies on the modeling of yard crane (YC) deployment for resource-limited container terminal. Firstly, the models for the basic yard crane deployment are proposed, which include the basic network flow model and the basic mathematical model. Secondly, the extended models are formulated, which can be utilized to deal with the deployment of multi-type yard cranes. Finally, numerical experiments are conducted to verify the effectiveness of the proposed models, e.g. functional test, performance analysis and scenario analysis.
Keywords: container terminal operation; yard crane deployment; network flow; resource limited; multi-type yard cranes.
Maintenance, repair, and operations inventory reduction and operational development
by Matias Siponen, Harri Haapasalo, Janne Harkonen
Abstract: Emphasis on maintenance, repair, and operations inventory (MRO inventory) can lead to improvements in inventory control and productivity while reducing operational costs. This study focuses on different approaches to optimising and reducing spare part inventories by addressing the development of MRO inventory operations and by analysing the development efforts of an urban energy company. The results indicate that typical challenges faced in inventory control are due to inadequate control and management policies and procedures. Three main viewpoints are emphasised to developing spare part inventory operations, with a broad focus, including: material management, supplier management, and information system management. The need to adopt business process management methods to enable successful continuous development of the spare part inventory processes is also highlighted. A potential framework for the MRO inventory management development process is developed as a result of the findings, and the role of correct roles and responsibilities within the organisation is highlighted.
Keywords: Inventory; spare part; maintenance; repair; and operation (MRO) inventory reduction; industrial and systems engineering; process development; process management.
On Supply Chain Contracts as Risk Sharing Mechanisms
by Siddharth Mahajan, Krishna Sundar Diatha
Abstract: In this paper, we consider risk and return in the buyback contract and the revenue sharing contract. Risk is measured by the variability in profits and return by average profits. We analyze the two firms in the supply chain using the Newsboy inventory model and standard results related to modeling of buyback contracts and revenue sharing contracts. We also use simulation. We show that the two contracts represent an opportunity for the manufacturer to increase return at the expense of taking a moderate risk. For the retailer, it is possible to benefit both ways in the two contracts. We show numerically that he can simultaneously get a higher return and a lower risk by entering into the two contracts. The manufacturers risk always gets increased with the two contracts. The retailers risk can get increased or lowered with the contracts. If the contract parameters are chosen such that the retailers risk gets lowered, then the contracts act as risk sharing mechanisms. They lower the higher risk of the retailer and transfer some of it to the manufacturer.
Keywords: Inventory; Supply Chain Coordination; Buyback Contract; Revenue Sharing Contract; Risk and Return.
Application of STAMP methodology in one complex manufacturing system
by Marcelo Santiago De Sousa, Felipe Martins Torres, Ariosto Bretanha Jorge
Abstract: The use of system theoretic accident model and processes (STAMP) is presented in this work in order to increase the efficiency in a production system. The motivation for this research is the possibility to apply STAMP together with the Lean philosophy and tools, to eliminate wastes in a production system. The main contribution of this study is based on the application of the methodology STAMP (commonly used for safety/security analyses and identification of accident causes) as a management tool. Besides assisting Lean on the wastes elimination, STAMP can help the process of taking decisions in a company. The results obtained and presented in this work show that STAMP methodology has the potential to be used together with the Lean approach, allowing the acquisition of more information than in the case where only Lean was used.
Keywords: manufacturing system; STAMP; systems engineering; production system; management; Lean philosophy.
Simulation modelling and development of analytic hierarchy process-based priority dispatching rule for a dynamic press shop
by Thenarasu Mohanavelu, Rameshkumar Krishnaswamy, Prakash Marimuthu
Abstract: In this paper, a detailed study has been made at an auto ancillary unit to prioritise the jobs in a press shop which accommodates 170 types of jobs and 27 press machines with different order quantities. The main objective of this work is to develop a simulation model of the press shop to study the performance measures such as lead-time, WIP, machine utilisation, and queue-related statistics and to develop an effective job priority system which improves the performance measures of the press shop. A novel analytic hierarchy process (AHP)-based priority dispatching rule is presented in this study by assigning weights to the factors such as due date, production volume and processing time. The proposed AHP-based priority rule is implemented in the proposed simulation model and it is found to be effective in improving the most of the performance measures considered in this study.
Keywords: job shop; analytic hierarchy process; AHP; discrete event simulation; ARENA; priority dispatching rules; PDRs.
Systematic evaluation for bottleneck detection methods
by Brian Huff, Mohammed AlMansouri
Abstract: This study will evaluate bottleneck detection techniques that have been identified in previous research by comparing the performance of each method on all case study models that can be replicated from the literature. The purpose of this analysis is to identify the most efficient and reliable bottleneck detection algorithm(s) which are capable of supporting constraint identification on a wide range of production system classes and configurations. The primary objective will be to identify a robust bottleneck detection algorithm, or a small set of algorithms, that can be broadly applied to various types of production or service provision environments. Discrete-event simulation will be used to support this algorithm evaluation task and will also play a key role in the application of bottleneck detection methods in real-world production scenarios.
Keywords: production system; bottleneck detection; simulation; theory of constraint; production activity control.
Scheduling batch processing machines in a no-wait flow shop using ACO to minimise the makespan
by Miguel Rojas-Santiago, Shanthi Muthuswamy, Purushothaman Damodaran, Mario C. Velez-Gallego
Abstract: This paper considers a two-stage flow shop scheduling problem with a batch processing machine (BPM) in each stage. The processing time of the batch on the first machine is equal to the longest processing job in the batch, and the batch processing time on the second machine is equal to the sum of processing times of all the jobs in the batch. The jobs cannot wait between the two stages. The problem under study with the makespan objective is NP-hard. An ant colony optimisation (ACO) algorithm combined with batch forming and local search heuristics is proposed and its solution is compared with: a particle swarm optimisation (PSO) algorithm; a greedy randomised adaptive search procedure (GRASP) algorithm; and a commercial solver used to solve the mixed-integer linear formulation. The experimental study helps to highlight the advantages, in terms of solution quality and run time, of using ACO to solve large-scale problems.
Keywords: no-wait flow shop; batch processing machines; BPMs; ant colony optimisation; ACO; makespan.
The vehicle routing problem with one-dimensional loading constraints
by Junmin Yi, Zhixiong Su, Yihui Qiu
Abstract: This paper proposes a vehicle routing problem with one-dimensional loading constraints, originating from a pick-up route planning of milk-run operations in the automotive industry. With analysis on milk-run routing-loading decisions, a wall-building approximation method is applied to vehicle loading, and then the routing problem is introduced as a new CVRP problem with special constraints of one-dimensional loading rather than the 3L-CVRP's full dimensional loading, hence a 1L-CVRP problem emerges. The 1L-CVRP instances with case data are solved by genetic algorithms and discussions are conducted on results, approximation error study and application conditions. With its modelling, solution and application, the systematic scheme of this 1L-CVRP is aimed at enriching the newly-proposed nL-CVRP framework with more dimensionality and instances. In addition, this study also serves as a straightforward paradigm for real-world logistics routing and loading applications.
Keywords: loading constraints; packing problem; dimensions; genetic algorithm; milk-run; wall-building; approximation; vehicle routing problem; VRP.
Effect of green supply chain management on production costs, quality and productivity using structural equation modelling
by Fariba Maadanpour Safari, Manouchehr Omidvari
Abstract: Green supply chain management (GSCM) has emerged as an important organisational philosophy to achieve corporate profits and market share objectives to reduce environmental risks and improve environmental performance. Due to recent changes in environmental requirements, development and deployment of GSCM becomes more and more evident. Currently, many organisations integrate environmental enforcement activities in their strategic plans for competitiveness and define numerous activities and actions that have less environmental effect. This study first characterises enforcement activities of the GSCM; then, it examines effectiveness of GSCM activities on cost, quality and productivity of manufacturers using structural equation model in a case study in the glass industry and tests the relationships between elements of the model.
Keywords: green supply chain management; GSCM; production costs; quality; productivity; structural equation modelling; SEM.
Assembly quality analysis method research of automotive body outer cover panels
by Kuigang Yu, Zhihong Yang
Abstract: This paper proposes an assembly variation modelling method of automotive body sheet metal parts for the assembly quality analysis of outer cover panels. In this method an influencing relationship between the measurement point variation and assembly locating unit variation is constructed through the space motion analysis. The gap and flush between two outer cover panels are two direction distances of their involved two measurement points near the gap. When the assembly variation of one gap or flush is analysed, only the locating variation of locating units that influences the gap or flush will be considered. One case application of a fender and a front door demonstrates the assembly quality analysis process of outer cover panels. Three steps are given when an assembly analysis of a gap or flush is dealt with. The given case analysis results that compares with commercial soft computation results show the feasibility of this method. By these computation results the assembly quality of outer cover panels can be predicted, and the optimisation of locating units also can be achieved.
Keywords: outer cover panel; sheet metal; assembly variation; assembly modelling.