International Journal of Industrial and Systems Engineering (95 papers in press)
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 optimisation model for sustainable blood supply chain network design under uncertainty
by Zahra Mohammadian-Behbahani, 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.
ModelLing 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.
Sequencing platform derivatives under operational and market constraints
by Emmanuel D. Adamides, Dimitrios Koumanakos, Vasilis Hadjipandelis
Abstract: Although there has been considerable amount of research on the design of product platforms, not much research has been pursued on how to exploit platform designs in changing business environments. Related to the latter issue is the problem of planning the sequence of platform derivatives launchings that corresponds best to market requirements and satisfies the operations constrains imposed by the platform design and the firms strategy. This paper addresses this problem and proposes a method for planning the introduction of a platforms derivatives to market. The method is based on the assessment of the sequence of moves (switching) between product-segment pairs by using an integrated hypernetwork-based representation of the knowledge related to the products, operations and market(s).
Keywords: product-launch sequencing; platform products; operations-marketing interface; operations strategy.
Design and experimental analysis for quantitative glue-pouring system of aluminium electrolytic capacitor
by Tian-Chi Zheng, Zi-Xue Qiu, Jian-Xin Shao, Guan Lu, Jiang Yuan
Abstract: Aiming at the problems existing in the glue-pouring process of capacitor aluminium shell such as glue solution uneven heating, glue easy carbonization, low accuracy of glue-pouring and so on, a new method for quantitative glue-pouring of aluminium shell is proposed. And, the quantitative glue-pouring system of aluminium electrolytic capacitor is designed, including melt glue machine, gear pump, quantitative glue-pouring mechanism, human-machine interface, PID intelligent temperature control unit and so on, and the mechanical structure of the melt glue machine and quantitative glue-pouring mechanism is designed detailedly. Incremental PID intelligent temperature control unit is introduced, and the simulation analysis of the temperature control system is conducted, the simulation results show that the temperature control has high precision, good adaptability; and the experimental analysis of aluminium electrolytic capacitor quantitative glue-pouring system is carried out, the analysis results show that the system has high precision and good stability. The system has been put into practical production use, operation results show that the maximum error of the system is 1.2%, which meets the requirement of quantitative glue-pouring for aluminium shell, and the system has good practical application value.
Keywords: aluminium electrolytic capacitor; aluminium shell; quantitative glue-pouring; experimental analysis; PID control.
Computational experiment of methods to determine periodic (R, Q) inventory policy parameters: a case study of information decentralised distribution network
by Kanokwan Singha, Jirachai Buddhakulsomsiri, Parthana Parthanadee
Abstract: This paper presents a case study of inventory management at distribution centre for hundreds of herbal products in Thailand. Differences in multiple products are characterised in terms of movement and demand variation. The incoming lead time from the manufacturer is time varying. The distribution network is information decentralised such that the distribution centres use replenishment orders from over 2,200 stores and hospitals to represent the end-customer demand. With the lack of real time inventory control system, the distribution centres implement a periodic (R, Q) policy for each item. The challenge is to properly set the parameters of the inventory policy for each product to minimise the total inventory management cost. Five methods with different degrees of computational requirement are implemented. An enumeration distribution is used to model the demand during varying lead time due to the lack of fits of widely used probability distributions. A computational experiment on the case study data is performed where method performance is evaluated through simulation. Statistical analysis of the results is conducted to identify the most effective methods to determine the inventory policy parameters.
Keywords: inventory control; iterative approach; distribution network; stochastic demand; varying lead time.
Job Shop Production System to a Manufacturing Cellular System: An Action Research Study
by Carina Pimentel, Sandra Martins, Joao Matias
Abstract: Organisations are motivated to improve their production flow. This is achieved by a better use of resources, including equipment, people, and materials. The process of changing production systems is a priority for manufacturers in order to make production more efficient. Cellular manufacturing systems provide several different kinds of benefit over traditional production systems, allowing better customer satisfaction. This paper describes a real company changing process from a job shop production system to a manufacturing cellular system, using simple but effective Lean practices and tools and following an action research methodology. The achievements obtained by the introduction of the manufacturing cellular system are presented, and compared with the previous system. The improvements achieved were substantial in terms of production organization, production levels, quality levels, customer satisfaction and workers self-esteem. Careful selection of the parts and of the human resources are two critical factors for success.
Keywords: Job shop; Cellular manufacturing; Lean manufacturing; Lean practices and tools; Action research; Trial technique.
Continuous improvement of injection molding using Six Sigma: case study
by Ahmed Maged, Salah Haridy, Saleh Kaytbay, Nadia Bhuiyan
Abstract: Plastic injection molding is considered as one of the very challenging processes to obtain output with a good quality and low cost. This paper presents a case study of the deployment of Six Sigma in plastic injection molding to improve the quality of the final product by eliminating major defects occurred using cost effective methods. The main objective is to identify the major quality problems and to eliminate root causes by adopting Six Sigma Define, Measure, Analyze, Improve and Control (DMAIC) methodology. The proposed Six Sigma approach effectively integrates quantitative and qualitative tools such as Statistical Process Control (SPC) charts, Pareto chart, histogram, Ishikawa diagram, measurement system analysis, hypothesis test and checklist to achieve the desired goal. The results reveal that the implementation of the proposed Six Sigma approach can reduce the rejection rate significantly. It is found that the quality of the final products is substantially improved in terms of sigma level which increased from 4.06 to 4.5 and the Cost of Poor Quality (COPQ) is reduced by 45%.
Keywords: Six Sigma; DMAIC; SPC; Injection molding.
Layout design optimisation with point cloud object modelling for multi-robot industrial working cell
by Ankit Sharma, A.K. Jha
Abstract: The paper proposes a multi-robot cell design method by integrating the concepts of computer aided design, optimisation and point cloud modelling in the layout planning problem. The point cloud data of machines and robots have been used through a Matlab programming interface to generate the optimal layout design. The minimum angular displacement of robot joints is the optimisation criterion, and Axis Align Bounding Box collision detection method has been used to obtain accurate solutions. The developed layout is validated against the data collected from the case study of an industrial robotic cell.
Keywords: Multi-robot cell; optimisation; point cloud modelling; CAD.
Designing an Optimal Bonus--Malus System Using the Number of Reported Claims, Steady-State Distribution, and Mixture Claim Size Distribution
by Amir Payandeh, Mansoureh Sakizadeh
Abstract: This article, in a first step, considers two Bayes estimators forrnthe relativity premium of a given Bonus--Malus system. It thenrndevelops a linear relativity premium that closes, in the sense ofrnweighted mean square error loss, to such Bayes estimators. In arnsecond step, it supposes that the claim size distribution for arngiven Bonus--Malus system can be formulated as a finite mixturerndistribution. It then evaluates the base premium under a Bayesianrnframework for such a finite mixture distribution. The Loimarantarnefficiency of such a linear relativity premium, for severalrnBonus--Malus systems, has been compared with two Bayes andrnordinary linear relativity premiums.
Keywords: Bonus--Malus system; Relativityrnpremium; Bayes estimator; Weighted mean square error; Loimaranta efficiency.
USER VALUE ANALYSIS OF A TWO WHEELER (SCOOTER)
by M. Muzammil, Mohit Gaur
Abstract: ABSTRACTrnValue is considered as an important parameter of User Acquaintance (UA). Life Values tended to influence attitudes and behavior which user values were viewed as subgroups of life value. In this study, user value elements of a two wheeler (scooter) were excerpted from life value elements using a survey sampling method. A total of 32 subjects who participated in the study were divided in three groups namely male participants and female participants and a group comprising of both male and female scooter drivers. An IBM SPSS statistics software was used to analyze the data collected. On the basis of the study it was found that there were twenty five user value elements for a two wheeler (scooter). These were comfort, competence, satisfaction, independence, cheer, convenience, intelligence, salvation, Family security, Cleanness, Money, Freedom, Logic, Accomplishment, Trust, Self-control, Social Recognition, Justice, Courage, Ambition, Confidence, Responsibility, Individuality, Appearance, and Happiness. rn
Keywords: Value analysis; user acquaintance; life value elements; two wheeler; user value element.
Research on TBF Distribution Model of Circular Tool Magazine and ATC
by Xiaohong Lu, Song Wang, Yanfei Lu, Nan Li
Abstract: Tool magazine and automatic tool changer (ATC) is one of the most important function units of a machining center, its reliability directly influences the performance of the machining center. Failure analysis is the basic work in reliability study. So far, there are few studies on failure of the tool magazine and ATC. Based on the failure data obtained from the field tracing of a kind of circular tool magazine and ATC, the probability density function, the distribution function and failure function of time between failures (TBF) of the tool magazine and ATC are calculated. It is preliminarily assumed that the TBF of the circular tool magazine and ATC obeys Weibull distribution. Parameter estimation and hypothesis testing of the Weibull distribution model are done. Finally, the effectiveness of the model is verified. The work can provide a reference for failure prediction of circular tool magazine and ATC.
Keywords: circular tool magazine and ATC; TBF; distribution model; linear relation testing; hypothesis testing.
DEVELOPED PRIORITY RULES SUPPORT SYSTEM FOR ELSP: A CASE STUDY
by Mohammed M. El-Beheiry, Khaled S. Abdallah
Abstract: Economic Lot Size Scheduling Problem (ELSP) is one of the most challenging problems in production and operation management. Although studied extensively in the literature, yet it is still one of the major topics in scheduling research. ELSP with its various configurations can be found in many industrial fields. In this paper, a producer of Fast Moving Consumer Goods (FMCG) is considering this decision. The company has a production line producing a range of products having dependent changeover cost. It is required to determine the production schedule and lot size that minimize the total cost. A new heuristic model is developed that uses different priority rules to find the best lot size that minimizes the total cost. The new model is then simulated to analyse and compare the performance for the different rules with different lot size. The results of the case study used shows that choosing the scheduling policy relies on a suggested cost ratio threshold which is a function of the cost parameters of the operation. The effect of different cost parameters on the performance of different priority rules is also discussed.
Keywords: ELSP; Priority Rules; Simulation; FMCG scheduling;.
An integrated fuzzy analytical network process for prioritization of new technology-based firms in Iran
by Maysam Khodayari, Jafar Razmi, Reza Babazadeh
Abstract: The performance evaluation and prioritization of knowledge-based firms which are working in science and technology parks enable the decision makers (DMs) to specify the benchmarks (the best firms) and grant them or help other firms to improve their performance. In this paper, the performance of new technology-based firms (NTBFs) in Iran is evaluated through a multi-criteria decision making method. To do so, at first the most suitable criteria to assess the performance of the NTBFs are proposed according to the literature and experts opinions. Then, due to complex relation and correlation among the presented criteria, an integrated fuzzy Analytical Network Process (ANP) is proposed to evaluate NTBFs under uncertainty of evaluation parameters. The results show that the applied approach is a suitable tool for prioritization of NTBFs.
Keywords: New Technology-based Firms; Science and Technology Parks; Analytical Network Process (ANP); Fuzzy Set Theory; Performance evaluation and prioritization.
Integrated Scheduling of Part, Tool and Automated Guided Vehicles in a Flexible Manufacturing System Using Modified Genetic Algorithm
by NAVEEN KUMAR, Pankaj Chandna, Dheeraj Joshi
Abstract: Scheduling of part and tools without considering material handling devices may result in non-implementable results as the material handling system constraints affect the overall scheduling. In this paper, an attempt has been made for the simultaneous scheduling of part, tool and two automated guided vehicles (AGVs) in a flexible manufacturing system which has identical machines with no on-board tool magazine. All the tools are stored in a common tool magazine and are shared among different machines through a material handling system. Each tool type is single in number. The problem has two interrelated problems; one as loading and scheduling of part and tool and other as scheduling of AGVs. Two heuristics namely priority dispatching rules (PDRs) and modified genetic algorithm (MGA) with three parent crossover are used to find the optimal solution to the integrated scheduling problem. Both PDRs and MGA use an algorithm based on the concept of Giffler and Thompson procedure and a heuristic approach to generate the active feasible schedule. The performance of the two proposed algorithm is compared for the results of makespan. It was found that the MGA gives better results.
Keywords: Integrated scheduling; Flexible manufacturing system; Modified genetic algorithm; Automated guided vehicle; Makespan.
Integrating considerations of uncertainty within the OEE of a manufacturing line
by Marcello Braglia, Davide Castellano, Marco Frosolini, Mose Gallo
Abstract: Lean Manufacturing has become a paramount production paradigm in many industrial sectors and Overall Equipment Effectiveness (OEE) is a widely accepted and adopted lean metric for any type of machine/equipment. However, the standard OEE formulation presents two important limits: (i) it deals with a single machine, and (ii) gives a deterministic measure of effectiveness. The objective of this paper is to overcome both of these two shortcomings by proposing a Fuzzy approach for measuring the OEE of a manufacturing line (OEEML). Hence, starting from a possible definition of OEEML, this paper provides a framework to measure its modal value and its variability on an entire manufacturing line. The approach exploits Fuzzy Triangular Numbers instead of burdensome stochastic quantities to measure this variability. Furthermore, it integrates a method which enables us to avoid the annoying overestimation effect of FTNs. The integrated approach has proved to be useful in consistently capturing the OEEML variations, also, both the modal value and the range obtained from its application are good estimators of both the OEEML and its variability. A full case study is finally provided to show the effectiveness of the proposed approach in diagnosing problems and addressing improvement actions.
Keywords: Lean Manufacturing; Overall Equipment Effectiveness; OEE; Stochastic; Variability; Manufacturing Line; Fuzzy Triangular Numbers; Overestimation.
An Integrated Multi-Response Optimization Route Combining Principal Component Analysis (PCA), Fuzzy Inference System (FIS), Nonlinear Regression and JAYA Algorithm: A Case Experimental Study on Machining of GFRP (Epoxy) Composites
by Kumar Abhishek, V. Rakesh Kumar, Saurav Datta, S.S. Mahapatra
Abstract: Machining (drilling) operations have been performed on Glass Fibre Reinforced Polymer (GFRP) (epoxy) composites. The work intended to evaluate the most favourable setting of controllable process parameters which could simultaneously satisfy multi-requirements of process performance yield; in view of product quality as well as productivity. During drilling, three process parameters viz. drill rotational speed, feed rate and drill diameter have been considered to optimize thrust, torque and delamination factor (entry and exit both), simultaneously. Owing to the limitations of traditional Taguchi method based optimization approaches, the study proposes an integrated optimization module combining Principal Component Analysis (PCA), Fuzzy Inference System (FIS), nonlinear regression and JAYA algorithm towards optimizing correlated multi-response features during machining of GFRP (epoxy) composites. Application potential of the aforesaid integrated optimization route has been compared to that of Teaching-Learning Based Optimization (TLBO) algorithm; good agreement has been observed.
Keywords: Glass Fibre Reinforced Polymer (GFRP); Taguchi method; Principal Component Analysis (PCA); Fuzzy Inference System (FIS); nonlinear regression; JAYA algorithm; Teaching-Learning Based Optimization (TLBO) algorithm.
Benchmarking Model to Analyse ISCM Performance of Selected Indian Manufacturing Industries using Fuzzy AHP Technique
by Kailash, Rajeev Kumar Saha, Sanjeev Goyal
Abstract: Competing globally with world class industries, Indian manufacturing industries need to brace itself with benchmarking models and continuous self-improvement. Internal supply chain management (ISCM) performance may be focussed in particular to create a niche over others. Proper understanding of key performance indicators of ISCM is necessary to analyse the gaps. A suitable methodology is also required to interpret the loopholes in order to remove them. A combined approach of fuzzy logic and analytic hierarchy process (AHP) technique is used for better result of theoretical benchmarking model. Comparison control bar charts are also used to view the performance gap between internal supply chains of selected manufacturing competitors. The primary purpose of this paper is to identify worst performance measures by implementation of benchmarking model, fuzzy logic and AHP methodology.
Keywords: ISCM; KPI’s; benchmarking model; Fuzzy logic; MCDM; AHP technique.
Comparative Analysis of Different Vedic Algorithms for 8
by Rana Majumdar
Abstract: Multipliers are the basic building blocks of various processors; arithmetic and logical unit and they are widely used in digital signal processing and image processing applications such as convolution, DWT, DCT. In this paper, four separate algorithms for designing binary multipliers are adopted from the ancient Indian Book of Wisdom Sthapatya-veda (an Upa-veda of Atharvaveda). The current work mainly focuses on comparing the power, delay, LUTs (look up table), noise margin of different multiplier algorithms using various sutras of Vedic mathematics which has been implemented on Virtex 7 Board 1.1, using Xilinx Vivado version 14.2
Keywords: Delay; LUT; Power; Vedic Multiplier.
Identification of key lean practices within Indian automotive SMEs environment
by Rupesh Tiwari, Jeetendra Tiwari
Abstract: Purpose: SMEs are backbone of Indian economy, contributing more than 20 percent to GDP and providing employment to nearly 50 million people. With the increasing globalization, Indian SMEs (Small & medium-sized enterprises) are facing stiff competition both in and out of the county by the big players in particular. Indian SMEs are suffering from scarcity of vital resources and latest technical knowhow. Its imperative for them to use resources judiciously by implementing lean manufacturing. Its not feasible for SMEs to implement all the lean practices like big players. The objective of current study is to identify key lean practices for the Indian automotive SMEs to reap the maximum benefits out of it. Factor analysis was applied to identify independent lean practices because the various lean practices suggested by the different researchers are found overlapping and confusing in nature. Multiple regression analysis is used to identify the key lean practices which Indian SMEs can afford and must implement. Customer involvement is the most important practice followed by problem identification & prevention, total productive maintenance, and others. The novelty of this study emerges from identification of key lean practices within automotive Indian SMEs environment using statistical analysis. The finding of this study will serve as vital input for lean functional deployment.
Keywords: Lean manufacturing; Key lean practices; Factor analysis; Multiple regression; Sustainable strategic advantages; Small & Medium sized enterprises.
AN ALGEBRA APPROACH FOR NONLINEAR MULTIVARIABLE FED-BATCH BIOPROCESS CONTROL
by María Cecilia Fernández, Maria Nadia Pantano, Santiago Rómoli, Daniel Patino, Oscar Alberto Ortiz, Gustavo Scaglia
Abstract: In this paper, a linear algebra based controller design is proposed. This technique allows tracking, with minimum error, predefined optimal profiles in nonlinear and multivariable systems. To achieve this, control actions are obtained solving a linear equation system. The controller parameters are selected with a Monte Carlo algorithm. The methodology is applied in a fed-batch penicillin production process, where the control action is the feed flow rate and the tracked profiles are the concentration of biomass, product and subtract inside the reactor. Different tests are shown to prove the good performance of the controller adding: parametric uncertainty and perturbations in the control action and in the initial conditions.
Keywords: Nonlinear dynamics control; fed-batch fermentation; penicillin production; profiles tracking control.
Simulation-based Optimization Model for Paired-cells Overlapping Loops of Cards with Authorization (POLCA) system
by Saeed Abdolmaleki, Masoud Kasaee, Sajjad Shokouhyar
Abstract: Companies with high variety of high-mix products are interested in having smoother production flow to cope with tardiness, to this end, they have been looking for an effective Production and Material Flow Control (PMFC) system to gain competitive advantages. In practice, Paired-cells Overlapping Loops of Cards with Authorization (POLCA) system has had a great remarkable success. This paper deals with a simulation-optimization approach to evaluate POLCA control system in workshops before implementing it.
Keywords: Discrete Event Simulation; Optimization; POLCA.
Using simulation to reshape the maintenance systems of caster segments
by Rossella Pozzi, Margherita Pero, Roberto Cigolini, Francesco Zaglio, Tommaso Rossi
Abstract: The maintenance of steel mills has a relevant impact on costs and productivity of steel industry. Caster segments are the key components of the slab caster and they have to be maintained on a regular basis to ensure a high steel quality. According to the traditional approach, one crew per shift takes care of the maintenance of each segment. This way of doing requires the operators to be skilled in all the phases needed to repair a segment, while process control is very limited and performance indexes (productivity, lead-time, etc.) hit very low levels. This paper introduces a new approach to repair caster segments that makes each segment move along a disassembly and then assembly line where specific attention has to be paid to shared resources. The methodological approach is based on simulation, which has been applied to a real-life case study, represented by a leading Indian steel mill. Simulation is exploited, first, to point out the effect of the concurrent requirement of resources, demonstrating that a static sizing can lead to wrong designs, then, to properly consider the variance of execution times. Results show that caster maintenance arranged in a line designed according to the proposed methodology remarkably contributes to speed up the maintenance process and that the number of segments needed to run the line is reduced, leading to a corresponding reduction of operative working capital by about 16 million $.
Keywords: Simulation; maintenance; steel mills; flow line.
Scheduling an Assembly Job Shop Production System with Multiple Objectives: A Simulation Study
by Midhun Paul, R. Sridharan, Radha Ramanan T
Abstract: This paper presents the salient aspects of the performance analysis of two mechanisms for shop floor control namely; Order Review/ Release (ORR) and dispatching rules in an assembly job shop system in a multi-objective environment. A simulation model of an assembly job shop is developed for experimentation with eight dispatching rules and four ORR mechanisms from the literature. An ORR policy based on the concept of backward scheduling and interval release is developed and incorporated in the simulation model. Grey relational analysis is used for ranking the ORR policy-dispatching rule combinations. Multivariate and univariate hypotheses are developed. The results are analyzed using ANOVA and MANOVA. Grey relational analysis used for ranking the ORR policies-dispatching rule combinations. The results are subjected to univariate and multivariate hypotheses. The analysis of results reveals integrating dispatching rules with ORR policies provides better system performance than using dispatching rules alone. The proposed ORR policy namely, backward scheduling with interval release policy provides better results than other ORR polices.
Keywords: Assembly Job Shop; Simulation; Scheduling; Multi-Objective; GRA.
Analytical Approximations to Predict Order Picking Times at a Warehouse
by Maria Hulett, Purushothaman Damodaran
Abstract: The primary objective of this research was to develop analytical approximations to predict the time taken to complete a customer order in a warehouse. The problem under study was modeled as a network of queues and the parametric decomposition approach was adopted to develop the approximations. Under this method, the queuing network is decomposed into individual queues allowing to analyze single (i.e. customer order processing, pallet building, and re-pick process) and fork-join stations (i.e. order picking with synchronization constraints) within the same framework. Analytical formulations to estimate order picking times were developed and compared with equivalent simulation models to estimate the accuracy of the formulations. Appropriate correction terms were also developed to bridge the gap between the analytical approximations and the simulation models. The experimental study conducted indicates that the analytical approximations along with the correction terms can serve as a good estimate for the order picking times in a warehouse.
Keywords: Queuing networks; Parametric decomposition approach; Fork and join queues; Warehouse order picking;Analytical formulations; Markovian Systems; Different product classes; Flow time; Simulation models; Correction terms.
Improving production systems with lean: A case study in a medium-sized manufacturer
by Sérgio Vieira, Rui Borges Lopes
Abstract: Lean principles and tools have been increasingly employed in companies across several sectors, with numerous successful implementations both inside and outside production environments. In the case of Portuguese companies, few works have reported the application and corresponding results of lean, and even fewer focusing on small and medium sized companies.
This work presents a case study of an implementation of several lean principles and tools in the production sector of a Portuguese medium-sized screw cap manufacturer. Visual management, A3 thinking, and single-minute exchange of die (SMED) were employed to identify and reduce inefficiencies and waste in the shop floor. The implementation of these principles and tools is detailed, showcasing the necessary adjustments for being correctly embedded in the companys culture. Qualitative and quantitative results are presented concerning the case study, where a continuous improvement culture was adhered to and a significant gain in productivity could be observed.
Keywords: Lean tools; case study; bottle cap industry.
MIP based heuristic algorithm for finite capacity MRP problem in hybrid flow shop with unrelated parallel machines.
by Watchara Songserm, Teeradej Wuttipornpun
Abstract: A main drawback of the material requirement planning system (MRP) is that it assumes fixed lead time, resulting in capacity problems recently called finite capacity MRP (FCMRP). This paper proposes a mixed integer programming (MIP) based heuristic algorithm that can solve the industrial scale FCMRP problem in hybrid flow shop with unrelated parallel machines. The heuristic is applied to construct an initial sequence of operations, whereas the MIP model is applied to determine the optimal machines and start times for the operations based on the initial sequence. The objective is to minimise the total cost, defined as the sum of tardiness, earliness, idle time, and work in process holding costs. Performances of the proposed algorithm are evaluated using real data from automotive industries. The result shows that the total cost of the proposed algorithm is substantially reduced, compared with the recent FCMRP algorithm (HGATS). Moreover, the required runtime is within a practical limit.
Keywords: Mixed integer programming; Finite capacity MRP; Hybrid flow shop; Unrelated parallel machines; Application in industry.
A Firefly Algorithm for the Heterogeneous Fixed Fleet VRP
by Panagiotis-Petros Matthopoulos, Stella Sofianopoulou
Abstract: Vehicle routing is a key success factor in logistics problems. A variation of Vehicle Routing problem (VRP), the heterogeneous fixed fleet VRP in which the vehicles available for distribution activities are characterized by different capacities and costs, is tackled. A hybrid firefly algorithm for optimizing the routing of heterogeneous fixed fleet of vehicles in logistics distribution systems is presented. The principles and key steps of the proposed firefly algorithm are introduced in detail. Experimental results from solving the heterogeneous fixed fleet vehicle routing problem when tested on benchmark datasets are demonstrated. Moreover, the algorithm is compared with other algorithms solving similar problems in order to prove the effectiveness of the proposed hybrid firefly algorithm.
Keywords: Firefly algorithm; Nature Inspired Metaheuristic Algorithms; Combinatorial optimization; Vehicle routing problemrn.
A reliable and computationally efficient model for professional gas boilers
by Emidio Tiberi, Riccardo Furlanetto, Daniele Turrin, Marzio Piller
Abstract: Gas boilers can be integrated into professional ovens for steamcooking
processes. Their heat-transfer efficiency depends on several parameters,
as exhaust gas temperature, combustion stability, fuel type, excess air.
Computational Fluid Dynamics (CFD henceforth) provides a viable option
to assess several digital prototypes of gas boilers under different operation
conditions. Short setup-time, low computational cost and close matching with
experimental results are key features of a CFD model suitable for the industrial
We propose a reliable and computationally-efficient CFD model for gas boilers,
operating under steady conditions. The model does not take explicitly into account
both combustion and water boiling.
The accuracy of the proposed model is confirmed by the excellent agreement
between experimental measurements of the exhaust gas temperatures and the
corresponding numerical results.
Keywords: gas boilers; CFD; heat transfer; experimental validation; computational efficiency.
Evaluating the Effectiveness of Spare Parts Replenishment Methods for Warranty Service Satisfaction
by Andrew H. Bluett, Hector A. Vergara, J. David Porter
Abstract: After a mobile communication device (MCD) has been sold, the customer may find that there is a defect. MCD manufacturers usually contract a third-party warranty service provider (WSP) to perform repairs of manufacturing defects and to ship a repaired MCD back to the customer. The contract established between the MCD manufacturer and the WSP clearly specifies the minimum required service levels for repair lead time and fill rate that must be met by the WSP. In this research, the ability of two distinct spare parts replenishment methods to meet minimum required service levels at a minimum cost was evaluated using a discrete event simulation approach. The results show that both methods satisfy minimum service level requirements with no significant difference in average total system cost. However, the results also indicate that their performance with respect to average repair lead time and average fill rate is significantly different.
Keywords: discrete event simulation; mobile communication device; spare parts replenishment; inventory management; replenishment planning; warranty service.
Optimal buffer allocation for serial production lines using heuristic search algorithms: A comparative study
by Leyla Demir, Alexandros C. Diamantidis, Deniz Türsel Eliiyi, Michael E. J. O'Kelly, Semra Tunali
Abstract: The buffer allocation problem (BAP) is one of the major optimization problems faced by production system designers. BAP is widely studied in the literature since buffers have a great impact on efficiency of production lines. This paper deals with buffer allocation problem and compares the performance of three heuristic search algorithms, namely myopic algorithm (MA), degraded ceiling (DC), and adaptive tabu search (ATS) with respect to both throughput maximization and also computational time. To generalize experimental findings the experiments have been conducted both for reliable and also unreliable serial production lines over various sizes of problem instances. It is hoped that the findings of this research study can serve as a guideline for the decision makers while designing and operating production lines.
Keywords: Production lines; Buffer allocation problem; Tabu search; Myopic algorithm; Degraded ceiling.
Sustainability Modeling of Health Information Exchanges in Dynamic Environments
by Abdulaziz Ahmed
Abstract: Healthcare practitioners have realized that sharing patient data is beneficial, which can be accomplished by joining a Healthcare Information Exchange (HIE) network. Many challenges confront those joining an HIE network, and one of the most serious is the networks financial sustainability. This paper develops three linear programming models to study the sustainability of an HIE network. Two types of agent are considered: the Healthcare Provider (HCP) and the HIE network owner. Model 1 aims to maximize the benefits for HCPs, while Models 2A and 2B are intended to maximize the benefits for HIE owners. The results of Model 1 showed that the benefits for HIE owners and HCPs were positive. In Models 2A and 2B, the benefits for HIE owners were sometimes negative because in some cases there were not enough joined HCPs. This study helps decision makers understand the sustainability of HIE networks in a dynamic environment.
Keywords: Healthcare information exchange; linear programming; optimization.
An Online Quality Monitoring Tool for Information Acquisition and Sharing in Manufacturing: Requirements and Solutions for the Steel Industry
by Satu Tamminen, Eija Ferreira, Henna Tiensuu, Heli Helaakoski, Vesa Kyllönen, Juha Jokisaari, Esa Puukko, Juha Röning
Abstract: The purpose of this study was to develop an innovative online supervisor system to assist the operators of an industrial manufacturing process in discovering new solutions for improving both the products and the manufacturing process itself. In this paper, we discuss the requirements and practical aspects of building such a system and demonstrate its use and functioning with different types of statistical modelling methods applied for quality monitoring in industrial applications. The two case studies presenting the development work were selected from the steel industry. One case study predicting the profile of a stainless steel strip tested the usability of the tool offline, while the other study predicting the risk of roughness of a steel strip had an online test period. User experiences from a test use period were collected with a system usability scale questionnaire.
Keywords: data mining; generalized boosted regression; GBM; quality improvement; online monitoring; knowledge representation; product design.
A Synergic Multivariate Statistical Process Control Framework for
Monitoring, Diagnosis, and Adjustment of Multiple Response Abrasive Machining Processes
by Sagar Sikdar, Indrajit Mukherjee, Subash C. Panja
Abstract: In various abrasive machining processes, output product quality is defined in terms of multiple critical characteristics (or responses) and their deviations from target values. These multiple characteristics or responses are often interacting or correlated. In such a situation, changing the process operating conditions for improving or controlling the quality of one response may deteriorate the quality of another. Thus, there is a need to simultaneously consider all responses and recommend a trade-off operating condition for process control and optimisation. Two important fields that consider simultaneous control and optimisation of multiple responses are the multi-variate statistical process control (MSPC) and multiple response optimisation (MRO). In the context of MSPC, there are three distinct phases of process control, namely, (i) correct identification of an out-of-control signal, (ii) identification of influential response variable(s) that contribute to an out-of-control signal, and finally (iii) re-establishment of the stability of the process by implementing necessary adjustments in the process setting conditions. Although various parametric and non-parametric MSPC and MRO solution approaches have been previously proposed, there is limited prior research work on the integration of the MSPC and MRO solution approaches to ensure the stability and process capability of the abrasive machining processes. In this study, a synergic MSPC and MRO approach is proposed, based on the Mahalanobis distance (MD), MahalanobisTaguchi system, r-control chart, seemingly unrelated regression (SUR) and non-linear optimisation technique, to ensure the stability and capability of the abrasive machining process. The suitability of the proposed approach is verified using a real life abrasive machining case data set.
Keywords: Abrasive Machining Process; Multivariate Statistical Process Control; Multiple Response Optimization; Mahalanobis-Taguchi System; r-control chart; Multivariate Process Capability.
Analytical evaluation of agile success factors influencing quality in Banking Sector
by Viral Gupta, Parmod Kumar Kapur, Deepak Kumar, Satya Prakash Singh
Abstract: Todays software applications deployed in an enterprise caters to the complex business processes, integrates various business units and addresses requirements of global customer base. The traditional methodology of software engineering succumbs towards the changing need of customer and technology advancement. Agile methodology targets complex systems with its iterative, incremental and evolutionary approach. There are numerous factors attributing towards the successful implementation of agile methodology. The measurement and evaluation of these agile success factors in an enterprise remains a challenge. This research paper presents a framework to analyse and measure the success factors of agile methodology in an enterprise, using Two-way assessment and Analytic hierarchy process (AHP). A case study has been conducted in a large enterprise in banking sector and twelve success factors of agile implementation have been evaluated and measured. The proposed framework makes significant contributions to the research community by providing improvement in the maturity of Agile implementation in an enterprise by 54%.
Keywords: Software Quality; Agile methodology; Two-way assessment; Analytic hierarchy process; Continuous integration; Enterprise application.
An Inventory System with Service Facility and Feedback Customers
by Amirthakodi M, Sivakumar B
Abstract: This article considers a single server queueing-inventory system with finite waiting room. The customers arrive according to a Poisson process. The individual customer's unit demand is satisfied after an exponential service time. After a customer is served, she will decide either to join the retrial group, which is of infinite orbit, for another service or leaves the system according to a Bernoulli trial. These orbiting customers compete for service according to constant retrial policy. The service time for these feedback customers are assumed to be exponential. The inventory is replenished according to an (s,S) policy and the lead times are exponential. We have carried out the busy period, waiting time and steady state analysis of the system. Some important system performance measures in the steady state are derived and the long-run total expected cost rate is also calculated. The results are illustrated numerically.
Keywords: (s,S)inventory policy; Finite Waiting Hall; Feedback customer; Constant retrial policy; Waiting time distribution.
An optimization framework of a global supply chain considering transfer pricing for a Colombian multinational company
by Juan Camilo Paz, John Wilmer Escobar
Abstract: This paper considers the problem of designing a global supply chain of consumer products by considering transfer pricing. It is based on a global established supply chain for which the central problem is to determine the closure and consolidation of national distribution centers. The problem has been solved by using a mixed integer linear programming model considering decisions regarding the location of facilities, transfer pricing, plant capacities, and the flow of products through the supply chain. The objective function of the proposed mathematical model is to maximize the total profit after tax by considering the determination of global revenues in the different facilities and their division over the chain. The mathematical model has been tested with real information obtained from a Colombian multinational company of the commercial sector. The obtained results confirm the efficiency of the proposed model by including transfer pricing and the positive impact on the determination of the profits of the case study company.
Keywords: Optimization of Global Supply Chains; Transfer Pricing; Tax; Logistics.
Risk control with options hedging for an oil import enterprise
by Yu Xing
Abstract: The paper examines the performance of several options hedging models, namely with currency options, with crude oil options and with both currency and crude oil options, for a crude oil importing firm. We simulate the returns, calculate optimal hedge ratios and suggest a risk management strategy. The empirical results show that the models of GJR-t and EGARCH-t are respectively suitable to forecast the volatilities for WTI crude oil price and exchange rates (CNY/USD). Student-t Copula is the best fitting function to describe the dependence structure among the bivariate return series. Furthermore, by comparing the risks measured by CVaR (Conditional Value at Risk), we suggest that the risk appetite investors can buy currency options for hedging and the risk aversion investors can buy crude oil options for hedging., it is not wise to buy both options of currency and crude oil in term of budget.
Keywords: Risk hedging; Optimization modeling; Simulation method; Conditional Value at Risk.
Building Sustainable Models and Assessments into Petroleum Companies: Theory and Application
by Ibrahim Garbie
Abstract: There is an urgent need to build a sustainable models to predict future in oil and gas sector to accommodate and respond to the short-term pressures. One of the main issues in petroleum companies is the concept of sustainability interpreted in a multitude of different ways. Numerous frameworks have been presented to assess sustainability, but there is no agreement on a common set of criteria for analysis, investigation, modeling and assessment. A framework of sustainability in oil and gas industry was built and investigated by two important levels: Micro-level and Macro-Level. The Micro-Level was proposed to evaluate sustainable index in single petroleum company and Macro-Level was suggested to assess sustainable index in the whole oil and gas sector. Practical indicators have been suggested and developed to assess sustainability indexes. An implementation of the suggested framework was applied through three big petroleum companies in Sultanate of Oman. The results shows that some companies had sustainable indices more than others.
Keywords: Oil and gas industry; sustainability; sustainable development.
A hybrid approach for modelling dynamic flows and systemic risks in supply chains
by Ke Sun, James Luxhøj
Abstract: The uncertainty of supply chain operations is becoming more complex with the growth of globalized business collaborations. Temporal business environment fluctuations cause disruptions that require quantitative risk analysis tools to understand and mitigate supply chain risks. This paper presents the formulation and application of the Dynamic Flow Bayesian Networks (DFBNs) and the Optimized Dynamic Flow Bayesian Networks (ODFBNs) for a three-stage supply chain. DFBNs are created by integrating Dynamic Bayesian Networks (DBNs) and System Dynamics (SD) to demonstrate the feedback flows of a supply chain with systemic risks considered. ODFBNs that incorporate mathematical optimization with the original DFBNs are also developed to generate an optimization-enhanced risk-influenced dynamic flow analysis. DFBN and ODFBN provide supply chain practitioners with a more effective reference for their business strategy. Comparison between the ODFBN and the DFBN is illustrated with a discussion of preliminary modelling results.
Keywords: supply chain; risk analysis; Dynamic Bayesian Networks; System Dynamics; multi-objective optimization; hybrid model.
Using social network analysis for industrial plant layout analysis in the context of Industry 4.0
by Leonilde Varela, Vijay Manupati, Suraj Panigrahi, Eric Costa, Goran Putnik
Abstract: Social network analysis (SNA) is a widely studied research topic, which has been increasingly applied for solving different kinds of problems, including industrial manufacturing ones. This paper focuses on the application of SNA on an industrial plant layout problem. The study aims at analysing the importance of using SNA techniques to study the important relations between entities in a manufacturing environment, such as jobs and resources in the context of industrial plant layout analysis. Here, performance measures such as maximum completion time of jobs (makespan), resource utilization, and throughput time have been considered to evaluate the system performance. Later, with the simulation analysis, the relationships between entities and their impact on the system performance is evaluated. The experimental results revealed that the proposed SNA approach supports to find the key machines of the systems that ultimately leads to the effective performance of the whole system. Finally, the identification of relations among these entities supported the establishment of an appropriate plant layout for producing the jobs in the context of Industry 4.0.
Keywords: Manufacturing systems; plant layout; social network analysis; case study.
An approach to assess robustness of reconfigurable manufacturing system
by Ateekh Ur Rehman
Abstract: A manufacturing system is considered, which produces thirty products using seventeen conventional machines and different process plans for each product. The system accepts customer orders for any combination of these products. These orders received from time to time may relate to different combinations of the products of varying quantities. The system is simulated using ProModel and the exercise helped in quantifying how the manufacturing system would perform under different scenarios characterized by the combinations of various operational features. The performance of the system is measured using performance measures such as machine utilization, through put time, product earliness, product lateness and product block time. Nine different alternative configurations were developed and simulated. Taguchi analysis led to some interesting inference, which appears to be extending good support to manufacturing system performance analysis. The details of the simulation model, analysis of the results and the inference drawn are presented in this paper.
Keywords: Performance evaluation; reconfiguration; simulation; ProModel; robustness; Signal to noise.
Fostering systematic eco-innovation in an Industrial symbiosis environment using DEMATEL
by Jayakrishna Kandasamy, Vimal KEK, Medha Vibha, Shubham Jain, Asela K. Kulatunga
Abstract: In todays rapidly changing and evolving world, manufacturing acts as one of the most important part for the development of any organization. This study is done in order to analyze the performance of any industry on the basis of opinions of industrial experts. Decision making trial and evaluation laboratory (DEMATEL) method has helped the industry to achieve benefits in business management by Eco-Innovation. Industrial Symbiosis helps different organizations to pool their resources, discuss their problems, their merits-demerits and also to share their profit. This study is mainly done in order to know about the different key points by experts who will enhance the performance of Industrial Symbiosis. These attribute can be used as the reference point to encourage the operational activity. This study collected information from sugar mill industry, paper mill and cement industry in Tamil Nadu, India. DEMATEL method is used to visualize the impact of different attributes on the company. It has wide range from very basic, such as to analyze the problem to finally getting the solution of problem. By using DEMATEL approach, proper graphs, data can be plotted which clearly shows the amount of effects each factors have on each other and on organization. Multi Criteria decision making (MCDM) also uses the DEMATEL properties in order to show interrelationship between different factors, to obtain a threshold value for further study.On the basis of DEMATEL approach Solid Waste Management(C3) with the largest R+C value=23.0 and Growth Rate=5.6396 as a smallest value are identified respectively. Company need to focus mostly on Solid waste management to in order to improve the efficiency in terms of eco-innovation and industrial symbiosis.
Keywords: Multiple attribute decision making; DEMATEL; Criteria interaction; sustainability; Eco-Innovation; Industrial Symbiosis.
Supply Chain Performance Measurement Systems: A Qualitative Review and Proposed Conceptual Framework
by Sharfuddin Ahmed Khan, Amin Chaabane, Fikri Dweiri
Abstract: MManagement of supply chain (SC) is becoming challenging by every passing day due to high competition, globalization, and digitalization because of the recent adoption of Internet of Things (IoT) technologies in order to increase supply chain visibility. Due to this fact, importance of supply chain performance measurement systems (SCPMS) has been increased significantly. To cope up with these challenges and remain competitive, organizations are keen to evaluate SC performance more precisely. Therefore, this paper adopts a qualitative review methodology to find out if existing SCPMS are in line with the current emerging technology trends of managing SC and measuring SC performance and if not, what will be the characteristics of future SCPMS. Results show particularly that existing SCPMSs are not adequate to cope up with the complexity and the technology advancement observed in Supply Chain Management as a smart way for measuring modern SC performance is needed. Finally, this study proposes a conceptual supply chain performance measurement (SCPM) framework to fill the identified research gaps.
Keywords: Supply Chain Management; Supply Chain Performance Measurement Systems; Knowledge Base System; Integrated Framework; Long-term Decision Criteria; Short-term Decision Criteria.
Adaptive Online Successive Constant Rebalanced Portfolio Based on Moving Window
by Jin'an He, Xingyu Yang, Hong Lin, Yong Zhang
Abstract: In the nonstationary financial market, considering earlier observations
may be little or irrelevant to the current investment decision-making, we design
two kinds of adaptive online portfolio strategies only based on recent historical
data. Firstly,we design an adaptive online portfolio strategy by linearly combining
the last portfolio and the best constant rebalanced portfolio corresponding to the
recent historical data, which we call moving window. We determine the length
of the moving window by adaptive learning. More precisely, we consider the
strategies that always adopt the best constant rebalanced portfolio corresponding
to the moving window of different fixed lengths as different experts, and at the
beginning of the current period, we choose the length ofmoving window the same
as the expert achieving maximum current cumulative return. Furthermore, we
determine the length ofmoving window by only using the recent historical data to
adaptively learn, and design another adaptive online portfolio strategy.We present
numerical analysis by using real stock data from the American and Chinese
markets, and the results illustrate that our strategies perform well, compared with
some benchmark strategies and existing online portfolio strategies.
Keywords: online portfolio selection; investment strategy; moving window; adaptive algorithm.
Supply Chain Coordination and Decision under Effort-Dependent Demand and Customer Balking Behavior
by Guangdong Liu, Tianjian Yang, Xuemei Zhang
Abstract: The paper explores supply chain coordination under a sales effort-dependent demand and customer balking scenario and analyzes the impacts of revenue- and cost-sharing contracts on the decisions of supply chain members. This paper subsequently develops a two-echelon supply chain consisting of one supplier and one retailer and examines two models that incorporate customer balking and sales efforts: in one model, the retailer offers a revenue sharing-only contract, and in the other model, the retailer and the supplier bargain on the revenue and cost-sharing contract. The results show that the revenue- and cost-sharing contract can coordinate the decentralized supply chain better than it can coordinate a centralized supply chain and that the effects of customer balking on the supply chain are clear; when customer balking occurs, the probability of a sale occurring can increase the profit of the supply chain, while the threshold of inventory and the sales effort can improve the marketing demand. In addition, a Pareto-improvement scenario and managerial decisions for supply chain coordination are derived from a numerical analysis.
Keywords: revenue- and cost-sharing contract; customer balking behavior; newsvendor model; Stackelberg game; effort-dependent demand.
Fleet Dimensioning and Scheduling in the Brazilian Ethanol Industry: A Fuzzy Logic Approach
by Henrique Ewbank, Peter Wanke, Henrique L. Correa
Abstract: This work solves a real-world multi-depot vehicle routing problem (MDVRP) with a homogeneous fleet and capacitated depots. A pipeline company wants to establish a vehicle policy in order to own part of its fleet and serve its customers for a period of 1 year. The company also wants to know the schedule of the visits for collecting ethanol from 261 producers and taking it to their three terminals located in Brazil. This problem presents uncertain demand, since weather conditions impact the final crop and uncertain depot capacity. Due to the vagueness of managers speech, this problem also presents uncertain travel time. Authors use fuzzy logic to model uncertainty and vagueness and to split the initial instance into smaller ones. Besides solving a real-world problem with fuzzy demand, fuzzy depot capacity and fuzzy travel time, this paper contributes with a decision making tool that reports different solutions for different uncertainty levels.
Keywords: multi-depot vehicle routing problem; fuzzy logic; job scheduling; real-world problem; expert system.
Innovation in ergonomics: a survey in the agribusiness sector of Brazil
by Raquel Kraemer Sabadin, Eliana Andréa Severo, Julio Cesar Ferro De Guimarães
Abstract: The healthy organisation corroborates participatory environments, innovative, centralised in the sense of human relations in the workplace, anthropocentric essence of ergonomics. The aim of this study is to analyse the relationship between innovations in ergonomics, absenteeism and in the risk of lifting loads in six units of an agribusiness. The method we used was a quantitative survey of a descriptive nature, survey type with a sample of 419 workers, which were used measures that explored the relationship between the study variables, through factor analysis and multiple linear regression. The results show that the workplace environment explains 46% the occurrence of process and organisational innovations in ergonomics, since the process and organisational innovations in ergonomics justify by 40% the significant reduction of absenteeism. Organisations have in its management processes the involvement of workers and make innovations that refine their performance and contribute to the human relationship in the workplace, which positively affect both, the organisation and the worker.
Keywords: Process Innovation; Organisational Innovation; Ergonomics; Absenteeism; Agribusiness; Brazil.
A General Variable Neighborhood Search for Multi-Skill Resource-Constrained Project Scheduling Problem with Step-Deterioration
by Huafeng Dai, Wenming Cheng, Wucheng Yang, Yupu Wang
Abstract: This paper proposes a general variable neighborhood search approach (GVNS) for solving the multi-skill resource constrained project scheduling problem (MS-RCPSP) under step-deterioration aiming to minimize maximum completion time. To assess the performance of the proposed GVNS, integrating five neighborhood structures and a disturbance step, computational experiments are carried out on two sets instances. One group takes no account of deterioration where the proposed GVNS achieved highly performance compared with the state-of-the-art algorithms in the literature, and the other group of experiments on modified dataset considering the step-deterioration effect also demonstrates the capability of the GVNS to find high quality solutions.
Keywords: deterioration effect; multi-skill; resource constrained project scheduling problem; general variable neighborhood search.
OPTIMAL MULTIVARIATE CONTROL CHARTS BASED ON LINEAR COMBINATION OF NORMAL VARIABLES
by Sandra García, Andres Plaza, Joseph León
Abstract: In some productive processes where normal variables intervene, it is necessary to control specific directions of shifts (increments or decrements) in the mean vector. Many multivariate control charts base their statistics on quadratic forms and do not rapidly detect a shift in a specific direction. In this paper, we propose two charts based on the linear combination of correlated normal variables, the LCN (Linear Combination of Normal Variables) and LCPC (Linear Combination of Principal Components). These charts were designed to detect a specific shift in the process. To analyse the performances of these charts, we have developed a friendly program that finds the best parameters through Genetic Algorithms. This algorithm minimises the out-of-control ARL (Average Run Length) for a proposed shift in the mean vector under the restriction of a desired in-control ARL value. The proposed control charts are Shewhart type, which show better performances than the Hotelling T2 chart.
Keywords: Control Chart; the Hotelling T2 control chart; Optimization; Principal Components; Normal Variables; Genetic Algorithm; Heuristic; Average Run Length; One-Sided Chart; Shewhart chart.
Back-projection Imaging Algorithm of Random Noise Frequency Modulation Continuous Wave SAR
by Xu Xingjian, Yuehua Li, Can Wang
Abstract: The combination of random noise frequency-modulation continuous wave technology and synthetic aperture radar(SAR) promises a cost-effective, low probability of intercept and high electromagnetic compatibility. This paper analyzes the time-domain restricting algorithms for random noise frequency modulation continuous wave (RNFMCW) SAR. Two versions of the back-projection algorithm are proposed. At first, the radar antenna continuous motion in a pulse repetition period of RNFMCW SAR is analyzed. Then the phase term which is caused by the continuous motion is described by a approximate expression with Taylor expansion. Meanwhile, both the start-stop approximate back-projection algorithm and the modified back-projection algorithm are proposed. In the end, with the help of numerical simulation, the limitations of the start-stop approximation back-projection algorithm and the validity of the modified back-projection algorithms are illustrated.
Keywords: random noise; FMCW; SAR; back-projection; Taylor expansion; correlation.
Comparison of AHP-TOPSIS and AHP-AHP Methods in Multi-Criteria Decision Making Problems
by Deepak Sharma, Srinivasan Sridhar, David Claudio
Abstract: Decision making is a highly researched topic and various methods have been developed to facilitate a decision maker in choosing the best alternative. Saatys Analytic Hierarchy Process (AHP) has been very popular since 1977 and has been adapted all over the world. However, AHP is a highly-debated topic. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is another Multi-Criteria Decision-Making (MCDM) method developed by Hwang and Yoon in 1981 as a ranking method. This research is focused on identifying which is the MCDM method between AHP and TOPSIS. Since TOPSIS is a ranking method, the authors propose to combine AHP and TOPSIS methods and determine which methods ranking (AHP, AHP-TOPSIS combination, and TOPSIS with equal weights) aligns more closely with the DMs initial preference. Moreover, this research states the efficiency of the method by comparing the time it takes to make a decision and its reliability.
Keywords: AHP; AHP-TOPSIS; Decision Maker Initial Ranking; Multi-Criteria Decision Making.
Performance Modelling and Optimization of the Rice Processing Industrial System using PSO
by Ajay Kumar
Abstract: The present work includes the performance modelling and optimisation of the rice processing Industry for achieving the maximum availability. The study presents a methodology for availability evaluation of the process industry. For the increased production rate and resource utilization, the maintenance plan should be developed which can predict the effect of performance parameters with time. The performance modelling for the Steady State Availability (SSA) has been done using Markov method using historical failure and repair database followed by the system optimization using Particle Swarm Optimization (PSO). The performance parameters are assumed to be negative exponential which are independent to each other and repaired units are considered as fine as original. The uncertainties of failure and repair rates (FRR) are removed by selecting these parameters randomly in PSO. The maximum availability of each system for all possible combinations of FRR within fixed minimum and maximum limits for each subsystem has also been computed. The rice processing plant consists of several subsystems for which optimum availability level for rice processing plant for random combinations of FRR has been found. The computed results are economically beneficial for the plant personnel in improving the production rate and maintenance planning.
Keywords: Performance modelling; Rice processing plant; Markov Modelling; Particle Swarm Optimization; Selection; Decision Support System.
Simulated Annealing Approach to Minimize Total Weighted Tardiness of Non-Identical Parallel Batch Processing Machines
by Rajani Kakkunuri, Christine Nguyen, Purushothaman Damodaran
Abstract: A variety of industries use Batch Processing Machines (BPMs) that can process multiple jobs simultaneously per machine. This research considers the scheduling of multiple jobs onto non-identical parallel BPMs while minimizing the total weighted tardiness. The problem under study is NP-hard and solving it to optimality using a commercial solver requires long run times when the size of the problem increases. A Simulated Annealing (SA) approach is proposed to find good solutions for large problem instances within short run times. The results obtained are compared to two metaheuristics, Particle Swarm Optimization (PSO) and Differential Evolution (DE), proposed in the literature and a commercial solver (CPLEX). An experimental study is conducted to evaluate the different solution approaches on a set of problem instances. Based on results, the authors conclude that SA is highly effective in solving large problem instances within reasonable run times when compared to CPLEX, PSO and DE.
Keywords: Scheduling; batch processing machines; weighted tardiness; simulated annealing.
The value of fleet information: A cost-benefit model
by Sini-Kaisu Kinnunen, Salla Marttonen-Arola, Timo Kärri
Abstract: Internet of Things (IoT) technologies enable the collection of wide-ranging data related to industrial assets which can be used as a support of decision making in asset management, varying from operative maintenance decisions concerning one asset to the management of asset fleets. Technologies and data-refining processes need to be invested in to create knowledge from the massive amounts of data. However, it is not clear that the investments in technologies will pay back, as the data analysis and modelling processes need to be developed as well, and the potential benefits must be considerable. This paper contributes to this field by modelling the costs and benefits of IoT investments. As a result, we develop a model that evaluates the value of fleet information in the maintenance context by applying the cost-benefit approach. The costs consist of hardware, software and data processing -related work costs, while the benefits comprise savings in maintenance and quality costs, as well as other savings or increased revenues. Testing the model with a descriptive case demonstrates that the realized cost savings and other benefits need to be considerable for the investment in IoT technologies to be profitable. The results emphasize the importance of data utilization in decision making in order to gain benefits and to create value from data.
Keywords: fleet; cost-benefit; asset management; investment appraisal; maintenance; life-cycle analysis; Weibull; life-cycle data; cost savings; value of information.
Meta-heuristics for Dynamic Real Time Scheduling of Diffusion Furnace in Semiconductor Manufacturing Industry
by M. Vimala Rani, M. Mathirajan
Abstract: It is observed from the literature that most of the earlier research in dynamic scheduling of diffusion furnace (DF) in Semiconductor Manufacturing industry, considers only future arrival of jobs. However, in reality along with the future arrival of jobs, various unexpected real time events related to jobs, and/or resources will occur. Hence, this study addresses the important real life characteristics of considering simultaneously both future arrival jobs and the occurrence of a job and/or resource related real time events while scheduling DF, called as dynamic real time scheduling (DRTS), with the scheduling objective of minimizing total weighted tardiness (TWT). This study first explains the mathematical model for dynamic scheduling of single diffusion furnace to minimize TWT. Since the research problem that is considered in this study is shown to be NP-hard, this study proposes meta-heuristics: Simulated Annealing (SA) and Tabu Search (TS) for DRTS of DF. In this study, for both SA and TS, six different initial solutions obtained from six variants of greedy heuristic algorithm (GHA) are given as input to improve the solution and this would result 12 variants of meta-heuristics (six variants of SA and six variants of TS). To find the most performing variants among the proposed 12 variants of the meta-heuristics, a series of computational experiments are conducted by empirically comparing the effectiveness with (a) best solution among the proposed 12 variants of the meta-heuristics, and (b) estimated optimal solution. In addition, the results obtained from the empirical analyses are further verified through two different statistical analyses. From empirical and statistical analyses on 270 problem instances, one of the proposed versions of the SA algorithm outperforms in comparison with the other proposed variants of the meta-heuristics.
Keywords: Simulated Annealing; Tabu Search; Greedy Heuristic Algorithm; Real Time Events; Dynamic Real Time Scheduling; Diffusion Furnace.
An Inventory Positioning Model under Vendor Managed Inventory System
by Jayalal Wettasinghe, Huynh Trung Luong
Abstract: Inventory management is one of the key functions in any supply chain. Since inventory cost occupies a significant portion of supply chain cost, it is essential to employ a good inventory policy in order to reduce the supply chain cost while improving the service level. This paper presents a vendor managed inventory (VMI) policy with emergency orders for a supply chain with a single vendor and two independent retailers. A mathematical model is developed using the concept of demand rate, assuming Poisson demand for the retailers. The formulated model is used to help determine the optimal system base stock level, delivery quantities to retailers and the cycle length such that the total expected inventory cost of the system is minimised. Numerical experiments and sensitivity analysis are then conducted to examine the effect of model parameters on total inventory cost and optimal solution.
Keywords: Vendor managed inventory; Emergency orders; Inventory management; Optimal base stock level.
Analysis of an M[X]/G(a, b)/1 queueing model with multiple vacation controllable arrival during multiple vacation and two phases of repair with delay
by T. Deepa, AYYAPPAN Govindan
Abstract: The objective of this paper is to analyse anM[X]/G(a; b)/1 queueing model with multiple vacation, controllable arrival during multiple vacation and two phases of repair with delay. Whenever the queue size is less than 'a', the server resumes multiple vacation and continues this until at least 'a' customers are waiting in the queue. After finishing a batch of service, if the server is breakdown with probability ?, the server will be sent for repair after a short interval of time called delay time. After this delay, two consecutive phases of repair (first phase repair, second phase repair) are considered. After the second phase of repair or when there is no breakdown with probability 1-?, the server starts a vacation if the queue length is less than 'a'. Otherwise, the server starts a service under the general bulk service rule. Using supplementary variable technique, the probability generating function of the queue size at an arbitrary time is obtained for the steady-state case. Also some performance measures and cost model are derived. Numerical illustrations are presented to visualise the effect of various system parameters.
Keywords: Bulk queue; Controllable arrival; Multiple vacation; Two phases of repair; Delay time to repair.
Simulation of incompressible flows in channels containing fluid and porous regions
by Pavel Bulat, Konstantin Volkov
Abstract: Flows and heat transfer in channels containing both fluid and porous regions play an important role in various engineering applications. A better understanding of fundamental mechanisms in the fluid flows in porous regions are required in order to design and optimise gas bearings, air filters, and thermal insulation in the specific applications. Darcy-Brinkman-Forchheimer model is used to describe the flow inside the porous domain. The finite volume method is applied to solve these equations in a porous and open domain. The capabilities of the mathematical model and computational algorithm are demonstrated using test cases from various areas of practical applications. The effect of various physical quantities on velocity and pressure distributions is studied. The results of the numerical simulation of flows in porous domains are presented. The results obtained are in a good agreement with the experimental and numerical data available in the literature.
Keywords: porous medium; computational fluid dynamics; channel flow; fluid injection; gas bearing.
Stability Analysis of Asynchronous Switched Positive Systems with Unstable Subsystems
by Jingjing Hu, Pingping Gu, Huiwen Liu, Dexiang Liu
Abstract: This paper investigates the stability problems of asynchronous switched positive systems based on mode-dependent average dwell time method in continuous-time context. While using mode-dependent average dwell time to study the stability of switched systems, each subsystem must be stable, otherwise a state feedback controller should be designed for the unstable subsystem. But in practical application, when the subsystem is activated one by one, it usually takes a period of time to identify which one of the state feedback controllers should be activated, which causes the asynchronisation. Next, in consideration of the difficulty of designing an appropriate state feedback controller for some unstable subsystems, this paper is aimed at obtaining the stability condition of asynchronous switched positive systems with both stable and unstable subsystems.
Keywords: asynchronization; mode-dependent average dwell time; stabilization; switched positive systems; unstable subsystem.
Generalized Fault Detection and Correction Modeling Framework for Multi Release of Software
by Avinash K. Shrivastava, Iqra Saraf, Javaid Iqbal
Abstract: The intense competition in the technology around the world has forced the software firms to speed-up their software upgrades. This arises challenges as the reconsideration in code may add new bugs/faults or the undetected leftover faults from previous release may create complications in getting the software updated. Due to added complexity, the testing team may be unable to correct the fault upon detection leaving the actual fault to reside in the software, termed as imperfect debugging or there may be addition of extra fault during correction process, known as error/fault generation. Also, change in testing strategies and resources at any time point may result in change in fault detection and correction rate which is known as change point. Keeping these issues under consideration, we propose, an NHPP-based general framework for multi-release, two stage fault detection and correction software reliability models under imperfect debugging, error generation and change-point. Proposed model is validated on real life data.
Keywords: Non-Homogenous Poisson Process (NHPP); Software Reliability Growth Model (SRGM); Detection; Correction; Modeling; Imperfect Debugging; Change-Point; Multi release; Ranking; Distance Based approach(DBA.
Operational strategies for managing container terminals. An approach based on closed queueing networks.
by Iñigo L. Ansorena
Abstract: The port performance can be improved by a well-defined operations plan. We present a closed Jackson network (CJN) approach to analyse port operations from vessel to yard. The tool is not only focused on the berthing line, but also on the service level at the storage yard. It aims to determine the best way to operate a containership using two crucial parameters: container stowage and truck traffic. Thus, the CJN model determines the impact of cargo stowage on port performance (1)) and the impact of traffic on port performance (2)). Both are crucial to set the best strategy and ensure the efficient use of handling equipments. The CJN model is flexible in the sense that managers may plan different scenarios. The study suggests that terminal operators can achieve substantial benefits by means of the best resource allocation in each scenario.
Keywords: Jackson network; resource allocation; container terminals; operations management; port performance; trucks; traffic; bay plans; service rate; berth productivity; yard productivity; queues; matlab.
A fuzzy multi-objective model for a cellular manufacturing system with layout designing in a dynamic condition
by Ali Mohtashami, Alireza Alinezhad
Abstract: Cellular manufacturing system (CMS) plays a remarkably significant role in modern production systems. This paper presents a novel and practical fuzzy multi-objective mathematical model for a CMS in a dynamic condition considering the flexibility in allocating machines. The proposed model seeks to determine the best layout design in each production period. Two conflicting objectives are considered including minimizing the cost of manufacturing system due to the amount of production loss caused by waste, as well as minimizing the variance of fuzzy costs. Due to the complexity of the problem, non-dominate sorting genetic algorithm-II and multi-objective particle swarm optimization algorithm are designed to solve the model and to obtain the effective solutions. In order to demonstrate the efficiency of the algorithms and to choose the premier algorithm, both algorithms are evaluated in several random problems and then compared based on the existing measurement indicators. Then, the algorithms are tuned to solve the problem, based on which their performances are analyzed statistically. The applicability of the proposed approach and the solution methodologies are demonstrated as well.
Keywords: Cellular manufacturing system; fuzzy theory; NSGA-II algorithm; MOPSO algorithm.
Mathematical Modeling for Prediction of Tube Hydroforming Process using RSM and ANN
by P. VENKATESHWAR REDDY, B. VEERABHADRA REDDY, P. Janaki Ramulu
Abstract: Tube hydroforming (THF) is a special manufacturing process used to produce tubular components having applications in aerospace and automotive industries. The present study investigates the effect of process parameters such as coefficient of friction (CF), corner radius (CR) of the die and the axial feeding (AF) of the punch. The bulge ratio and thinning ratio has been evaluated to minimise the defects like bursting, wrinkling and buckling in the tubes. Apart from many parameters, these parameters are chosen to know the effect of each individual parameter on the outcomes namely bulge ratio and thinning ratio. Each factor has varied with three levels and a total of 27 simulations were carried out based on full factorial design. RSM and ANN were applied on the obtained results in order to predict the process parameters effect on the tube hydroforming process. The R-square value of ANN (0.9524 and 0.9517) is much closure to 1 when compared to R-square value of RSM (0.9539 and 0.9509).
Keywords: Tube hydroforming; FEM; RSM; ANN; MATHEMATICAL MODELLING.
Effects of proof tests on the safety performance of safety-instrumented systems
by Asklou Noureddine, Noureddine Rachid
Abstract: The imperfection in the values of the average probability of failure on demand (PFDavg) creates uncertainty about the effectiveness of safety-instrumented system (SIS). To overcome this problem, many parameters such as dangerous failures, common cause failures, diagnostic coverage rate and proof tests are taken into consideration. In order to emphasise the importance of the proof tests and show their effects on the safety performance of the SIS, a new analytical formula is developed in this study. The impact of these tests on the SIS's allocation of the safe integrity level (SIL) is shown through the results obtained in the present research.
Keywords: Safety-instrumented system; proof test; average probability of failure on demand; safety integrity level.
Throughput Time Reduction for Transportation of Foodgrains in Public Distribution System: A Value Analysis Approach
by K. Mathiyazhagan, Ajay Bohtan, Prem Vrat
Abstract: Food security to the population of India is ensured by the public distribution system (PDS) which involves an enormous and complex supply chain, wherein after procurement from the farmers foodgrains are distributed to the intended beneficiaries. This paper has analysed the large through put time in a sector of the supply chain using value chain analysis approach which has led to re-appropriation of the flow by minimising the time taken by non-value adding activities thereby increasing the efficiency of the supply chain. Reduction in this throughput time would lead to various advantages including the reduction in cost of the supply chain. Further, the model so arrived at could be reworked to bring a similar reduction in the throughput time at the macro level of the entire PDS supply chain.
Keywords: Supply Chain Management; Public Distribution System; Value Addition; Value Analysis; Throughput time.
A Responsive Multiplicative Holt-Winters (RMHW) Approach for Enhanced Forecasting Accuracy
by H. M. E. Kays, A. N. M. Karim, Mohd Radzi C. Daud
Abstract: In the competitive world of todays business, the quest for a reliable forecasting method to predict the future events is an ongoing process. Accordingly, efforts are being made incessantly to come up with ideas of superior forecasting techniques. As a classical and reliable forecasting technique of Operations Research, the Conventional Multiplicative Holt-Winters (CMHW) approach has been widely adopted for the time series events having seasonal and other causal variations. To make a forecast, the CMHW approach incorporates three different recursion processes for updating and estimating the level, growth rate and seasonal patterns of the associated time series. A set of estimated initial values having the number of elements equivalent to the seasonal length is used to initiate the recursion process for the seasonal parameter. Whereas, the recursion processes of level and growth rate are initiated by using the individual single stationary values. However, dependency on the stationary single initial values reflecting a strong adherence to the preceding patterns of a data set might compromise the forecasting accuracy and responsiveness. While, modification of the CMHW approach by facilitating the periodic updates of initial values in the recursion process of level and growth rate is presumed to have positive effect in reducing the forecast error. In this context a Responsive Multiplicative Holt-Winters (RMHW) forecasting approach is proposed and presented in this paper for which the conventional recursion process of level and growth rate are adjusted dynamically by accommodating a periodic updating procedure. The proposed forecasting method is tested for validation through several sets of data collected from real-life industry and case studies extracted from literature. Interestingly, for all the cases the forecasting accuracy is found to be enhanced by applying the proposed RMHW approach.
Keywords: Seasonal patterns; Demand forecasting; Smoothing constants; Multiplicative Holt-Winters Method; Forecasting Accuracy.
Considering pricing and uncertainty in design of a reverse logistics network
by Mohsen Zamani, Mahdi Abolghasemi, Seyed Mohammad Seyed Hosseini, Mir Saman Pishvaee
Abstract: Companies try to maximize their profits by recovering returned products of highly uncertain quality and quantity. In this paper, a reverse logistics network for an Original Equipment Manufacturer (OEM) is presented. Returned products are selected for remanufacturing or scrapping, based on their quality and proportional prices are offered to customers. A Mixed Integer Non-linear Programming (MINLP) model is proposed to determine the location of collection centers, the optimum price of returned products and the sorting policy. The risk in the objective function is measured using the Conditional Value at Risk (CVaR) metric. CVaR measures the risk of an investment in a conservative way by considering the maximum lost. The results are analyzed for various values of the risk parameters (α, and λ). These parameters indicate that considering risk affects prices, the classification of returned products, the location of collection centers and, consequently, the objective function. The model performs more conservatively when the weight of the CVaR part (λ) and the value of the confidence level α are increased. The results show that better profits are obtained when we take CVaR into account.
Keywords: Reverse logistics; Network design; Pricing; Risk.
Using GRASP Approach and Path Relinking to Minimize Total Number of Tardy Jobs on a Single Batch Processing Machine
by Purushothaman Damodaran, Panteha Alipour, Christine Nguyen
Abstract: This paper considers scheduling a single batch processing machine such that the total number of tardy jobs is minimised. The machine can simultaneously process several jobs as a batch as long as the machine capacity is not violated. The batch processing time is equal to the largest processing time among those jobs in the batch. As the problem under study is NP-hard solving a mathematical formulation optimality is computationally intensive. A greedy randomised adaptive search procedure (GRASP) is proposed with the assumption of arbitrary job sizes, arbitrary processing times and arbitrary due dates. A novel construction phase for the GRASP approach is proposed to improve the solution quality. In addition, a path relinking procedure is proposed for solving large-sized problems effectively. The performance of the proposed GRASP approach is evaluated by comparing its results to a commercial solver and a construction heuristic. Experimental studies suggest that GRASP is superior compared to the commercial solver and the construction heuristic.
Keywords: Minimizing total number of tardy jobs; batch processing machine; scheduling; GRASP; path relinking.
Use of Industrial Robots in Developing Countrys Scenario; Evidence from Three Dimensional Wireframe Graphs of Production
by Ejaz Gul
Abstract: Globally, use of industrial robots increased by 60% in last decade. In case of developing country, use of industrial robots is a bit tricky. This paper presents a functional model to explain use of robots and productivity link for industrial environment of developing country. Presented model is based on three scenarios; human solo (existing), robot solo (substitute) and combination of human and robots (complement). Taking production P as dependent variable, we determined its mathematical value for three scenarios. After detailed analysis with a help of latest software GeoGebra and 3D wireframe graphs, we concluded that in human solo scenario, factory production remain low in short run but increases in the long run; in robot solo scenario (substitute), production increases in the short run but decreases in the long run more than human solo scenario; while production increases in short and long run when robots are used mixed with human effort.
Keywords: Robot; human; solo; substitute; complement; industry; production; short run; long run; increase; decrease.
Influence of Demographic Factors on Productivity: A study among employees with different personality types in architectural firms
by Sriram K. V, Zara Poursafar, Lewlyn L. R. Rodrigues, Mohammad Haghighatpanah
Abstract: Though productivity of an organisation is influenced by many factors like skill set, wages, qualification, etc. personality trait of an employee is an important contributor. The present research attempts to identify the significance of relationship between the demographic factors of the employees and the productivity in the office of architects with and without the consideration of personality traits of employees. The survey for the study was carried out in 80 architects' offices located in Iran and India. The data was collected through a self-administered survey questionnaire using random sampling method on the basis of representative sampling. Statistical analysis was carried out using SPSS ver. 20. Chi-square test was used to test association between demographic factors and productivity. The study shows that there is a significant influence of demographic factors on employees' productivity while taking into consideration the different personality types.
Keywords: Demographic factors; Productivity; Personality types; MBTI; Psychology; Architects offices.
The discrete analysis of relay-races
by Eugene Larkin, Alexander Privalov
Abstract: It is shown that relay-races as a form of concurrency, are widespread in such fields of human activity, as industry, defence, economics, politics, etc. The analytical description of J stages relay-races, in which participate M teams, is considered. The model based on the semi-Markov process theory allows investigating a process evolution in detail but is of little use for computer calculation of forfeit, which the winner team receives from loser teams. To adapt analytical description to computer calculations, the method based on sampling of continual time densities of passing stages is proposed. Due to the method, initial semi-Markov process is converted to semi-Markov process with degenerative distributions, and the task of forfeit calculation is reduced to the task of rigid schedules effectiveness analysis, in which schedules are selected stochastically from the densities samples. Formulae for the stochastic summation of forfeits, is obtained. The results may be used for optimal planning the activity of participant teams when passing the distance.
Keywords: relay-race; rigid schedule; semi-Markov process; degenerative distribution; evolution; distributed forfeit; recurrent procedure.