International Journal of Industrial and Systems Engineering (125 papers in press)
Optimisation of EDM process for MRR, TWR and Radial overcut of D2 steel: A hybrid RSM-GRA and Entropy weight based TOPSIS Approach
by Mohan Kumar Pradhan
Abstract: In this research, a distinct combination of Response Surface Methodology (RSM), Gray Relational Analysis (GRA) with Shannons entropy measurement based technique for order preference by similarity to ideal solution (TOPSIS) method has been suggested to assess, improve and estimate the influence of the process parameters on responses characteristics. Electrical Discharge Machining (EDM), the most versatile and commonly used non-traditional manufacturing process is considered in this study. The pulse current (Ip), pulse duration (Ton), duty cycle (Tau) and discharge voltage (V) were considered as the input parameters, whereas, Material Removal Rate (MRR), Tool Wear Rate (TWR) and Radial Overcut or Gap (G) were considered as the output parameters. This research highlights the development of a hybrid model to correlate the EDM parameters with the response obtained by the Shannons entropy based GRA-TOPSIS method. To justify the research ANOVA has been
used and it is found that the relative closeness was significantly affected by the
considered input parameters and some of their interactions. The R2 value for the
relative closeness was found to be 96.83 %. The ANOVA reveals that Ip is the most influencing parameter with 46.49% contribution followed by Ton, Tau and V with 13.92 %, 7.35 % and 2.8 %, respectively. The interaction of parameters contributes 15.26%. These results provide useful information to control the machining parameters and hence responses to ensure high productivity and accuracy of the EDMed component. Besides,this study can be used as a scientific source for parameter optimization in concerned manufacturing processes.
Keywords: Electrical discharge machining, Material removal rate, Tool wearrnrate, Radial overcut or Gap, Response surface methodology, Grey relationalrnanalysis, Shannons entropy, Technique for Order of Preference by Similarity tornIdeal Solution (TOPSIS)
A Final Note on the Ones Assignment Method and its Variants: They Dont Work
by Eric Landquist, Curtis Reigle, Francis Vasko
Abstract: Recently, Basirzadeh (2012) presented a new algorithm for solving the linear sum assignment problem that is called the Ones Assignment Method. It is similar to the Hungarian Method, but seeks to create, through division, ones in each row and column (instead of zeros as in the Hungarian Method) of the assignment matrix. Subsequent steps are analogous to the Hungarian Method. There have been several papers (Ghadle and Muley (2013, 2015), and Khalid et. al. (2014)), that have suggested modifications to the Ones Assignment Method. In this short paper, we provide a trivial assignment problem and show that neither the Ones Assignment Method nor any of its variants are able to find the optimal assignment to this problem which is obvious on inspection.
Keywords: Assignment problem; Hungarian method; Auction Algorithm; Ones Assignment Method; Optimization; Linear programming; algorithm; counterexample; additive strategy; multiplicative strategy
Price, production and order decisions in a one-manufacturer multi-retailer supply chain with fuzzy costs: Two parameter tuned meta-heuristics
by Mohammad Saeid Atabaki, Abolfazl Mirzazadeh, Saeed Fazayeli
Abstract: This paper develops a mixed integer nonlinear programming model of a one-manufacturer, multi-retailer, multi-period supply chain, where demands of retailers are affected by selling prices and learning curve is considered in production costs. Also, fuzzy concept is applied to cope with uncertainty of cost's parameters. Two meta-heuristic algorithms, namely genetic algorithm (GA) and invasive weed optimization (IWO) are proposed to solve the model. With optimizing parameters of the two meta-heuristics using Taguchi design of experiments, numerical examples showed that the proposed IWO has better performance in comparison with the GA. The IWO, then, is applied to solve the fuzzy model.
Keywords: Supply Chain; Nonlinear; Fuzzy; Genetic Algorithm; Invasive Weed Optimization; Taguchi.
Analytical Model of Information System Development Productivity in Adaptive and Perfective Maintenance Phases
by Kai Huang, Xiaoying Kong, Li Liu
Abstract: This paper presents an analytical model for Information System (IS) maintenance productivity in adaptive and perfective phases. The modelling approach is from economic view point. The productivity model considers the economic value of the maintenance phase, pre-committed fixed cost and variable cost consumed in adaptive/perfective maintenance. Influence factors to the productivity are analysed using simulation. The simulation provides a tool for IS project managers to tune the project parameters to obtain the optimal productivity in adaptive/perfective maintenance phases.
Keywords: analytical model, economic model, maintenance, productivity, IS maintenance management, simulation, software engineering
Energy and Magnetostriction analysis and Nonlinear Model of Magnetostrictive Actuator for Precision Drive
by Huifang Liu, Xingwei Sun, Quan Liang
Abstract: Magnetic hysteresis and eddy-current heating are the most significant disadvantages in giant magnetostrictive materials (GMM). And these properties have an effect on the displacement precision and other working performances of giant magnetostrictive actuator (GMA). To know and solve these above problems fundamentally, the key point is establishing a mathematical model which can describe magnetization hysteresis process and energy loss characteristics for GMM and analyzing the essential reason which causes hysteresis phenomenon. In this paper, on the basis of Armstrong theory and through analyzing the composition of elastic Gibbs free energy, a nonlinear magnetization and magnetostriction model is established. Experimental results show that this model can predict the magnetization property, magnetostriction, magnetic potential orientation, energy loss characteristic and other working performance for GMM well. It is also able to describe the magnetostrictive elongation and output displacement for GMM rod and GMA respectively. Research results will provide a theoretical basis for solving magnetic hysteresis, working precision, and eddy current heating for GMA fundamentally.
Keywords: GMA, Model, Magnetostriction, Magnetic hysteresis
PERFORMANCE ANALYSIS OF A DISCRETE-TIME GEO/G/1 RETRIAL QUEUE UNDER J-VACATION POLICY
by Shweta Upadhyaya
Abstract: We have investigated a discrete-time Geo/G/1 retrial queue under J vacation policy and general retrial times, which can be applicable to many digital systems viz. broadband integrated services digital network (B-ISDN), asynchronous transfer mode (ATM) and circuit-switched time-division multiple access (TDMA) systems. In discrete-time systems, we consider time to be a discrete random variable and measure it in fixed size data units such as machine cycle time, bits, bytes, packets, etc. The server follows J vacation policy according to which as soon as the retrial orbit becomes empty and no new customer arrives then the server may take at most J number of repeated vacations. The server immediately returns from the vacation if at least one customer arrives in the system. The inter arrival time is assumed to be geometric distributed whereas retrial time, service time and vacation time are assumed to be general distributed in the discrete environment. The underlying Markov process is analyzed by using generating function method whereby we obtain various performance measures of interests. We provide stochastic decomposition laws for the system size of the developed model.
Keywords: Keywords: Discrete-time retrial queue, Bernoulli feedback, starting failure, J vacation policy, Stochastic decomposition.
Fuzzy Control of an Industrial Process System using Internet and Web Services
by Hanane Zermane, Hayet Mouss
Abstract: This paper illustrates the development of an Internet-based fuzzy control system of one of complex industrial manufacturing processes, which is cement production. This system can ensure in the same time the remote and the fuzzy control of the process in real time in different cement factories in Algeria. The remote control system contains several tasks and options as diagnosis of alarms generated during the running of workshops, e-maintenance and synchronising different regulation closed loops to guarantee the automated performance. In addition, to evolve the system, we propose firstly, an artificial intelligence technique which is fuzzy logic, where we integrated the fuzzy control of different workshops of kiln and the two mills, which ensures that the system is operational at all times, with minimal downtime. Secondly, we integrated Internet technology, where the remote control via Internet, used for security of human life and rendering it unnecessary for operators to be at the site for maintenance. In addition, when there is a breakdown it is not necessary to send an expert to diagnose and solve the problem because it is difficult to organise visas, flight, etc. Therefore, the proposed system reduces downtimes and travel costs by the possibility of sending reports and transmitting all process data. The process control system contains different operators stations, alarms tables and trends analysis. The operator can execute any operation according to his authentication access. Operators can monitor the process control system in the main control room or via Internet.
Keywords: Process control; Data acquisition; Fuzzy control; Remote control; Reports transmission; Telecontrol.
Fuzzy Goal Programming Approach on Location-Routing Model for Waste Containers
by Salih Aka, Gökhan Akyüz
Abstract: In this study, an application about determining the location of recyclable waste containers was executed in Siteler District part of Konyaalti Municipality in Antalya, Turkey. For this problem, a location-routing model based on fuzzy goal programming was built. The aim of this study was to select optimal location nodes, which serve the maximum number of dwellings from candidate locations nodes and also, to create a minimum-distanced route between selected nodes. The containers of recyclable waste were located on optimal nodes of the route obtained by the mathematical model, which was run for different tolerance ranges and different priority structures.
Keywords: Multi-objective location models, the location-routing problems, fuzzy goal programming
Economic Design of Exponentially Weighted Moving Average Chart with Variable Sampling Interval at Fixed Times Scheme incorporating Taguchi Loss Function
by Ineen Sultana, Imtiaz Ahmed, Abdullahil Azeem, Nitish Ranjan Sarker
Abstract: A Control chart is a graph used to study how process changes over time. The Exponentially Weighted Moving Average (EWMA) chart is highly useful for not only detecting small changes in process parameters but also in inspecting individual unit observations. The objective of this paper is to develop an economic statistical design of the exponentially weighted moving average (EWMA) chart using variable sampling intervals with sampling at fixed times (VSIFT) control scheme considering preventive maintenance and Taguchi Loss function to determine the values of the seven test parameters (i.e., the sample size, the fixed sampling interval, the number of subintervals between two consecutive sampling times, the warning limit coefficient, the control limit coefficient, exponential weight constant and the time interval of preventive maintenance) such that the expected total cost per hour is minimized. A mathematical model is developed to analyze the cost of the integrated model. Nelder-Mead downhill simplex method and Genetic algorithm approaches are applied to search for the optimal values of the seven test parameters for the economic statistical design of VSIFT EWMA chart and Nelder-Mead downhill simplex performed better than Genetic algorithm. A hypothetical example and its solution are provided to have a better understanding about the demonstration of the proposed model.
Keywords: EWMA control chart; VSIFT scheme; Economic-statistical design; Taguchi Loss function; Preventive maintenance; Nelder-Mead downhill simplex method; Genetic algorithm
A Probabilistic Granular Tabu Search for the Distance Constrained Capacitated Vehicle Routing Problem (DCVRP)
by John Willmer Escobar, Rodrigo Linfati, Gustavo Gatica
Abstract: We address the well-known Distance Constrained Capacitated Vehicle Routing Problem (DCVRP) by considering Euclidean distances, in which the aim is to determine the routes to be performed to fulfill the demand of the customers by using a homogeneous fleet. The objective is to minimize the sum of the variable costs associated with the distance traveled by the performed routes. In this paper, we propose a metaheuristic algorithm based on a probabilistic Granular Tabu Search (pGTS) by considering different neighborhoods. In particular, the proposed algorithm selects a neighborhood by using a probabilistic discrete function, which is modified dynamically during the search by favoring the moves that have improved the best solution found so far. A shaking procedure is applied whenever the best solution found so far is not improved for a given number of iterations. Computational experiments on benchmark instances taken from the literature show that the proposed approach is able to obtain high quality solutions, within short computing times.
Keywords: Probabilistic Granular Tabu Search (GTS), Distance Constrained Capacitated Vehicle Routing Problem (DCVRP), Metaheuristic Algorithms, Vehicle Routing Problems.
Empirical analysis of bus travel time reliability: a case study in Shanghai
by Yangbeibei Ji
Abstract: Travel time reliability is one of the most important indications of quality of service in bus systems. The Automatic Vehicle Location (AVL) data of two typical bus routes in Shanghai are used to analyse bus travel time reliability. One bus line is in urban area and the other is in suburban area. Five reliability indices are used to capture the various characteristics of bus travel time fluctuations, which are planning time, buffer time, buffer time index, punctuality index based on routes and deviation index based on stops. The results indicates that peak hours have more obvious impact on travel time reliability and longer distance between adjacent stops causes higher buffer time at off peak hours. Bus in suburban area has more stable travel time than bus in urban area. The travel time reliability control measures are suggested at the end.
Keywords: Bus Travel Time; Travel Time Reliability; Bus Stops; Automatic Vehicle Location Data.
A Simulation Based Multi-Objective Optimization Approach in Flexible Manufacturing System Planning
by Arash Apornak, Sadigh Raissi, Mehrdad Javadi, Neda Ahmadizadeh, Ahmad Kazem
Abstract: In this paper, an attempt has been made to address the optimum set of queues capacity, queues discipline, conveyors and transporter's speed and operational setup times in a common flexible manufacturing system (FMS) with objectives of minimization of average stay time in queues and maximization of throughput simultaneously. Analysis of such issues, especially when the objective functions cannot be described in mathematical terms is a complex task is focused in this paper. Here the mean of five objective functions estimated by fitness functions extracted experimentally using 36 scenarios on a valid computer simulation model. Under equal weights, the exact solution attained by the Lingo software and optimum process setting achieved. The applicability of the new approach is ascertained through a case study involving the optimization of real engineering system and presented using the proposed approach.
Keywords: Design of experiment (DOE); Response Surface Modeling (RSM); Multi-objective optimization problem (MOP); Flexible Manufacturing system (FMS); Simulation
Modeling and Optimization of Process Parameters of Electrical Discharge Diamond Drilling of Nimonic Alloy-An aerospace Material
by UMacharan Singh Yadav
Abstract: An accent to existing electrical discharge machining (EDM) processes, the present authors have endeavoured to develop altogether a new process termed as electro-discharge diamond drilling (EDDD) and experimented with it for making the holes in nimonic alloy. This EDDD process together encompasses the concept of conventional twist drill, abrasion (micro-cutting) and electro-erosion. A hybrid approach of comprehensive models have been developed to overcome the usual difficulties of the lack in correlation between response parameters of material removal rate (MRR), average surface roughness (Ra), and average circularity (Ca), which confirm with adequacy of 99% confidence by Analysis of variance (ANOVA). The developed model consist of taguchi methodology (TM) coupled with response surface methodology (RSM) and has been termed as TMRSM. The model correlates the effects of interactions as well as of higher order of considered input parameters of tool electrode rpm, gap current, pulse-on time and duty factor. Thereafter, multi-objective optimization (MOO) of the EDDD parameters has been done with the combination of grey relational analysis (GRA) and principal component analysis (PCA) methodology and termed it as GRAPCA. In this methodology, the reference values of central composite rotatable design (CCRD) matrix of RSM model have been used to determine the values of grey relational grades, so as to further determine the values of optimum level of input parameters. The used hybrid EDDD process of machining along with using the hybrid approach of TMRSM as well as GRAPCA methodology for modelling and MOO is successful.
Keywords: Electrical discharge machining; Electrical discharge diamond drilling; Grey relational analysis; Principal component analysis; Response surface methodology; Taguchi methodology.
Application of logistics principles in management of travel agency
by Katarína Culkova, Erik Weiss, Andrea Rosova, Roland Weiss
Abstract: The contribution is focused on the application of logistic management algorithms for Travel agency sector. In the introduction the contribution explains the current state of the problem. As a methodology there is flash analysis, systems analysis and micro logistics analysis. The flash analysis points to the current position of the company on the local market, localization, its products, customers, competitors, mission, vision and strategic goals for the future. System analysis shows ongoing systems in the company. Results of contribution show algorithms of major processes in the company and a micro logistic model of the company. As a result of contribution measures are proposed, as for example a new Web site, modern reservation system and booking accounting system.
Keywords: travel agency; algorithm; flash analysis; system analysis; micro logistic model of the company; Slovakia
Unreliable Retrial Queue with Loss and Feedback under Threshold-based Policy
by Chia-Jung Chang, Jau-Chuan Ke, Fu-Min Chang
Abstract: In this paper, we consider an M/M/1 unreliable retrial queueing system with geometric loss and feedback under the threshold-based policy. Customers arrive at the system according to a compound Poisson process, and they are served immediately if the server is free; otherwise, they will enter a retrial orbit and form a single waiting line. After the customer is served completely, he may decide either to leave the system or to join the retrial orbit again for another service. If the server is found busy, the customer may either leave the system or join the retrial orbit for getting service. The server may be broken down at any time during the server is operating. When the server is broken down, it is not able to be repaired immediately until the number of customers in the system reaches a specified threshold value. The retrial system is modeled by a quasi-birth-and-death process, and some system performance measures are derived. The formulae for computing the rate matrix and stationary probabilities are derived by means of matrix-analytical approach. We obtain the optimal threshold value and the optimal service rate simultaneously to minimize the cost function of the system.
Keywords: retrial queue, quasi-birth-and-death, matrix-analytical.
A Decision Making using Data Envelopment Aggressive Formulation and Theory of Constraints to Enhance the PVC Production Line Performance
by Mohammed Shurrab, Abbas Al-Refaie, Nabeel Mandahawi, Shorouq Shurrab
Abstract: Bottlenecks and systems productivity are interrelated domains such that small changes in the bottlenecks could have a huge effect on the systems productivity. This research expounds a managerial case study combined a decision making data envelopment analysis (DEA) technique with the theory of constraints (TOC) systematic approach to a Polyvinyl Chloride (PVC) pipes production line. The true bottleneck was the low efficiency rate of the socketing machine which made the PVC pipes flow difficult during the production process. Four scenarios/solutions were applied to break the bottleneck constraint. DEA was utilized to recognize the optimal solution and make a proper decision. Upgrading the constraint, which was the last resort of TOC implementation, was the optimal solution. The deliverable of this solution was a significant enough performance improvement to break the constraint in the PVC production line. Although the optimal solution increased the incurred cost by 20%, it enhanced the number of the PVC pipes that are produced annually by 21%, increased the line throughput from 0.3 pipe/min to 1.15 pipe/min, and increased the system utilization by 19 % compared to the current situation scenario.
Keywords: Theory of Constraints; Simulation and Bottleneck Analysis; Process Based Costing; Data Envelopment Analysis; Decision making; and PVC pipes.
Application of Multi-Objective Genetic Algorithm to Aggregate Production Planning in a Possibilistic Environment
by Shahed Mahmud, Md. Sanowar Hossain, Dr. Md. Mosharraf Hossain
Abstract: The present study is to develop an interactive possibilistic environment based genetic algorithm for multi-product and multi-period Aggregate Production Planning (APP). APP is the prerequisite in order to make material requirement planning and/or capacity requirement planning accurately. The present study attempts to minimize the production cost and the rate of changing in labor level where production costs, backordering cost, labor level changing cost, demand are considered as imprecise parameters. It is noted that all these imprecise parameters are defined by the triangular possibility distribution. As the overtime production capacity is the fraction of available regular time production capacity, it is defined separately to make the result more acceptable. The proposed methodology is finally applied to demonstrate an industrial case in order to justify the feasibility. The solution obtained by the proposed methodology is compared with other solutions in context with computation efficiency and solution practicability.
Keywords: APP, Imprecise Parameters, MOGA, Possibilistic Environment, Practicability
Prediction of temperature variations using Artificial Neural Networks and ARIMA model
by Ali Namazian, Masoud Ghodsi, Khaled Nawaser
Abstract: Hydrologic processes modeling is a difficult but important affair, these are caused by parameters mutual effects, firstly because the reciprocal effects are numerous, and secondly the parameters interactions to create a complicated system. To predict hydrologic factors such as temperature, rivers flow, quantity of rainfall, air humidity and so on, for design and utilization water sources systems are necessary based on consideration of past and recorded statistical data, in configuration of time and place series. Time series analysis is a traditional prediction method, which is based on two assumptions, stationary and linear, non linear tendency is developed, too, in recent years. An artificial neural network is another prediction method, which showed to have proper ability for time series prediction in some cases. This paper in addition to reviewing two methods of variations of temperature abilities, namely Associated Related Integrated Moving Average (ARIMA), and Artificial Neural Networks (ANN), also compared both methods with each other for variations of temperature prediction of Gorgan city between 1970 to 2010 in Iran. The results indicated ARIMA method presented better estimations than ANNs estimations in relation to data with alternative processes of increasing and decreasing.
Keywords: prediction, artificial neural networks (ANN), Associated Related Integrated Moving Average (ARIMA)
Combat readiness evaluation of a fighter-jet using reliability and cluster analysis
by Panagiotis Tsarouhas
Abstract: We perform reliability analysis on a fourth generation fighter aircraft by taking into consideration its real flight conditions. The collection of the actual failure data was extended over a period of three years. Furthermore, the reliability function, the probability density function, the hazard function were estimated. The time between failures for all aircraft subsystems was evaluated. It was found that half of the failures were attributed to the engine, fuel, and electrical power subsystems. Overall, engine failures were more frequent and thus a quality analysis was undertaken. Commonalities of failure parameters were identified with a cluster analysis and were grouped in a dendrogram. Future research should look to further develop this concept for the evaluation of other types of military or civilian airplanes. This study may encourage air unit technical personnel to introduce a new combo problem-solving approach to systematically remove jet reliability blockers.
Keywords: Reliability, statistical analysis, failure data, fighter aircraft, cluster analysis
Using a Fuzzy MCDM Approach to Measure Project Complexity: A Case Study
by Ehsan Pourjavad, Rene Mayorga
Abstract: Evaluating project complexity is the main means for successful projects and can play an important role in improving the project management of companies that take on multiple projects simultaneously. Despite the importance of this subject, there are few studies in this field and project managers have not paid a great deal of attention to it. In this paper, an exploratory approach has been taken to identify key project complexity criteria which have been narrowed down to the following; project size, project variety, project interdependency, and project context-dependence. Also, a Multiple-Criteria Decision-Making (MCDM) method based on a Fuzzy Analytical Hierarchy Process (FAHP) is proposed to evaluate project complexity using the chosen criteria. Employing the Fuzzy AHP method in group decision-making facilitates a consensus of decision-makers and reduces uncertainty. An example of application is presented to display the utility of the model. The results reveal the usefulness of the proposed model in evaluating the project complexity in terms of complexity criteria. The findings also indicate the project variety and the project interdependency criteria have the highest impact on complexity of projects.
Keywords: Project Complexity; Multi-Criteria-Decision Making (MCDM),Fuzzy Analytical Hierarchy Process(FAHP); Evaluation.
The process flow optimization of crankshaft machining considering production logistics
by Xiaohong Lu, Song Wang, Shasha Wang, Lusi Gao, Likun Si
Abstract: In this paper, a typical crankshaft machining of piston compressor is taken as the research object. Based on System Handing Analysis(SHA), according to a series of problems existed in current actual production process, such as excessive materials handling time, Work in Process (WIP) overstock, unreasonable production layout, low utilization rate of equipment, high labor cost etc.., the process flow diagram method is adopted to research processing, handling, parking, waiting and checking processes in crankshaft production logistics. Reliable optimization of the production process is achieved via collection and analyses of time data in process flow. Through the researches on process flow optimization of crankshaft machining considering production logistics, the unreasonable processing technology of the crankshaft production and processing workshop is changed; through detailed analyses and optimization, process flow time of crankshaft production and processing is saved, the production efficiency is improved and the cost is reduced. The work done in this paper can provide reference for other products in process flow optimization of machining.
Keywords: Production logistics; Crankshaft machining; Process flow diagram method; Optimization; System Handling Analysis.
Fractional Order Model Reference Adaptive Control for SCARA Robot Trajectory Tracking
by Samir Ladaci, Yassine Bensafia, Khatir Khettab, Ahmed Chemori
Abstract: This paper proposes a new control strategy to the problem of trajectory tracking of SCARA robotic manipulator system by using a fractional order model reference adaptive controller (FMRAC) for sufficiently smooth trajectories.
Over the few last years the idea of introducing fractional calculus and systems in adaptive control has found a great interest, for the benefits one can win in the performances given by such systems. The main contribution of this paper, is to show that the proposed fractional adaptive controller is able to reduce the delay time and the overshoot existing in classical control approach. Simulation results illustrate the effectiveness of the proposed control approach comparatively to the classical integer order one.
Keywords: Fractional adaptive control; MRAC; SCARA robot; Trajectory tracking; Approximation methods.
Supplier selection using Improved Input Efficiency Profiling with Common Set of Weights (IIEPCSW) model
by Leyla Fazli
Abstract: The cost of the materials, parts and services received from outside constitutes the major cost of a product production. In such situations, purchasing departments can play a key and basic role in expenses reduction. The best suppliers' selection is one of the most important and basic duties of purchasing departments because of the basic role of suppliers performance on quality, cost, delivery and service, etc. Therefore, the use of accurate and efficient techniques to select the best suppliers is out of question. Hence in this study, a new prototype evaluation model called Improved Input Efficiency Profiling with Common Set of Weights (IIEPCSW) model is presented that provides a logical, reliable, consistent and efficient procedure to evaluate the potential suppliers of an item and select the best supplier (Single sourcing) under certain circumstance in single period. This model is a hybrid model based on Input Efficiency Profiling (IEP) model that improves the performance of IEP model and removes its shortages. Also, by validation is shown that IIEPCSW model is efficient and valid.
Keywords: Suppliers selection; Single sourcing; Single period; certain circumstance; Improved Input Efficiency Profiling with Common Set of Weights (IIEPCSW) model; Input Efficiency Profiling (IEP) model.
A novel approach based on relaxation and reduction to solve the capacitated lot sizing problem
by Mayank Verma, R.R.K. Sharma
Abstract: Capacitated lot sizing problem (CLSP) finds its applications in manufacturing, production as-well-as process industries. Typical size of the real life problems is much larger compared to the sizes that can be handled by commercial solvers, as CLSP is an NP-hard problem. Researchers have attempted different variants of CLSP in last few decades and provided many classical, exact, heuristic and meta-heuristic solution approaches. In this paper, we attempt to solve the multi item capacitated dynamic lot sizing problem with backorders and setup times (CLSPBS). We apply Lagrangian relaxation on the material balance constraint, to reduce the problem into several single constraint continuous knapsack problems with upper bound on the real variables. Bounded variable linear program determines the values of real variables. For the negative or positive value of coefficients in the Lagrangian function, we fix the setup variables at zero or one respectively. Thus the reduced problem is solved in polynomial time, as the main effort required is only sorting of numbers. We use the set up variable that are at one, to develop yet another good upper bound. Branch-and-bound procedure benefits immensely by using these bounds to make a warm start.
Keywords: Capacitated lot sizing; Lagrangian; bounded variable linear program; continuous knapsack problem; branch-and-bound.
New heuristic to generate an initial basic feasible solution for the balanced transportation problem
by Youssef Harrath, Jihene Kaabi
Abstract: This paper studied the balanced transportation problem. Many algorithms were developed to solve optimally this problem. The most commonly used method is the Modified Distribution Method (MODI). The MODI algorithm starts by generating an initial basic feasible solution using the Northwest Corner Method (NCM). In general the cost of the initial basic feasible solution generated by NCM is too high and far away from the optimal cost. For this reason, we propose in this paper a new method to generate an initial basic feasible solution to the balanced transportation problem to solve this issue. This method named Global Minimum Method (GMM) was tested and compared with the NCM, the Minimum Cost Method (MCM), the Vogels Approximation Method (VAM), and the optimal cost obtained by MODI. The computational results proved that the new heuristic is promising for small size instances and outperforms all other methods for big size problems.
Keywords: transportation problem; basic feasible solution; linear programming.
Online Fault Diagnosis in Partially Observed Petri Nets
by Liu Jf, Zhou Zh, Wang Zs
Abstract: This paper investigates the fault detection problem for Discrete Event Systems (DES) which can be modeled by Partially Observed Petri Nets (POPN). To overcome the problem of low diagnosability in the POPN online fault diagnoser in current use, we propose an improved online fault diagnosis algorithm that integrates Generalized Mutual Exclusion Constraints (GMEC) and Integer Linear Programming (ILP).We assume that the POPN structure and its initial markings are known, and the faults are modeled as unobservable transitions. First, the event sequence is observed and recorded. Then the ILP problem of POPN is solved for elementary diagnosis of the system behavior. While this system diagnoses that some faults may have happened, we also use GMEC for further diagnosis. Finally, we modeled and analyzed an example of a real DES to test the new fault diagnoser. The proposed algorithm increased the diagnosability of the DES remarkably, and the effectiveness of the new algorithm integrating GMEC and ILP was verified.
Keywords: Fault diagnosis; Partially Observed Petri Nets; Integer Linear Programming; Generalized Mutual Exclusion Constraints.
A novel genetic algorithm for the maximum coverage problem in the three-level supply chain network
by Bahman Naderi, Omid Rahmani, Mohammad Mohammadi, Mehrdad Nourri
Abstract: The maximum coverage problem is one of the most functional location issues. One of the competitive advantages for organizations is efficient and effective designing of supply chain network. On the other hand, given the importance of distribution planning among the levels of supply chain, vehicle routing problem needs to be explored which leads to a significant reduction in costs of supply chain network. The purpose of this research is designing a supply chain network that includes the supply, distribution centers and retailers. It should be noted that the coverage radius is defined for all distribution centers and distribution centers gives any services to retailers that is within the actual coverage. Also, this service is done on routing. Since the classical vehicle routing problem is NP-hard, to solve the problem in small sizes, we used the GAMS software and genetic algorithms and simulated annealing. Finally, the results have been evaluated.
Keywords: The Maximum Coverage Problem; Three-level Supply Chain Network; Genetic Algorithm; Simulated Annealing; Vehicle Routing Problem.
Soft computing method for minutiae-based fingerprint authentication
by Adhiyaman Manikcam, Ezhilmaran Devarasan
Abstract: In this paper, the fingerprint authentication is obtained by using fuzzy logic system which is based on bell shaped intuitionistic fuzzy number. The minutiae points extracted from fingerprint images which are treated as a fuzzy number. The important of the proposed work is to find out the two identical fingerprint images based on minutiae points, from these selects the optimal set and reduce the error points between the images using fuzzy logic system. The fuzzy system provides an adequate description of the proposed algorithm. The uniqueness of this process is consisting of a smaller number of calculations better than previous methods.
Keywords: biometric; fingerprint; minutiae extraction; fuzzy logic; intuitionistic fuzzy numbers; authentication system.
Modeling sustainable supply chain management problem with fuzzy demand based on multi-criteria decision making methods
by Mahnaz Mohebalizadeh, Ashkan Hafezalkotob
Abstract: Nowadays, environmental issues are playing a significant role in our real lives and need to be taken into account in many decision making problems. In order to incorporate environmental concerns into supply chain management problem as one of the most important decision making problems, a new sustainable supply chain model is developed in this paper in which collection/inspection, recycling and returning unsatisfying and for end of life products are examined in uncertain environment. In this regard a multi-objective mixed integer linear programming model with fuzzy demand parameter is proposed in which the flows through the sustainable supply chain network and facilities locations are determined in such a way that four objective functions are optimized including minimizing total cost, minimizing energy consumption, maximizing number of jobs, and minimizing delivery time. Using modified fuzzy parametric programming (MFPP) and weighted metrics as method the solution procedure to solve the developed model, it is implemented on a real case study to demonstrate its capabilities in practical context.
Keywords: Sustainable supply chain; sustainable development; multi objective problem; fuzzy TOPSIS; fuzzy programming.
Influence of process parameters on MRR, kerf width and surface roughness during WEDM on Inconel 718: Performance analysis of electrode tool material
by ANSHUMAN KUMAR, Kumar Abhishek
Abstract: In the present study, an attempt has been made to study the performance of (Brass wire electrode and zinc coated brass wire electrode) wire electrodes in relation to Material Removal Rate (MRR), kerf width and surface roughness of machined Inconel 718 obtained by Wire electro discharge machining (WEDM) process. Experiments have been conducted using L16 orthogonal array with two different types of wire electrodes and by tuning following controllable process parameters; discharge current, flushing pressure, wire tension, and pulse-on time. It has been observed that zinc coated brass wire produces lesser kerf width as well as surface roughness; higher MRR as compared to brass wire electrode. The pulse-on time is found to be the most singnificant factor on influencing MRR for all electrodes types. Pulse-on time and discharge current is found to be very singnificant on affecting kerf width for all electrodes types finally, Grey-Taguchi relational analysis have been adopted to establish the optimal parametric combination for both the wire electrode.
Keywords: Material Removal Rate (MRR); kerf width; surface roughness; Inconel 718; Wire Electro Discharge Machining (WEDM); Grey-Taguchi.
Lin-Sontag and common Lyapunov functions for stabilizing control of a switched nonlinear systems
by Abdessmad Abdelhadi, Wided Saadi, Driss Boutat, Lassaad Sbita
Abstract: This work presents a control of switched nonlinear systems. The approach is based on stabilization by using control Lyapunov functions. A necessary and sufficient condition for stabilization, based on the existence of a common Lyapunov control function for switching subsystems, is presented in first time. Secondly, a stabilization control device is designed for non-linear switching system using the theory of common Lyapunov function and state feedback control of Lin-Sontag. Finally, this proposed approach is illustrated on the example of a switched reactor.
Keywords: Switched systems; Stabilization; Control; Lyapunov Functions; Reactor.
The influence of different quantity discounts on integrated supplier-retailer inventory model
by Yu-Jen Lin, Shwu-Huey Lin
Abstract: This paper investigates an integrated inventory model with defective items where the supplier will offer different quantity discounts to the retailer by different defective rate. We consider the supplier has to offer all-units quantity discount to retailer, as the retailer inspects the receiving items are too highly defective rate. Otherwise, the supplier offers price-break quantities discount to the retailer. Our objective is to determine the optimal order quantity of the retailer and the optimal number of shipment per production run from the supplier to the retailer, so that the joint total profit has a maximum value. An algorithm is developed to find the optimal solution. Two examples are provided to illustrate the theoretical results, and the management insight is presented to demonstrate from the numerical examples.
Keywords: integrated inventory system; quantity discount; defective items.
A robust possibilistic programming model for simultaneous decision of inventory lot-size, supplier selection and transportation mode selection
by Atousa Zarindast, Seyed Mohamad Seyed Hosseini, Mir Saman Pishvaee
Abstract: As a result of the uncertain changes in global currencies, exchange rates have become a critical part of suppliersselection problem.In the present paper the problem of supplier, transportation mode selection and inventory replenishment decision(STSI)in the presence of uncertain changes of currency exchange rates and price discounts have been studied. The present article addresses the STSI problem for a buyer sourcing a product from heterogeneous suppliers. Global suppliersselection procedure is based on the prices that suppliers offer in their local currencies.Late deliveries and rejections also exert influence on sourcing and inventory replenishment decisions. The proposed model is a bi-objective mathematical programming, objective functions of which are minimizing the total cost and the late delivery of items.In order to cope with uncertain parameters effectively, a robust possibilistic programming approach is utilized. Finally, to assess the robustness of the solutions obtained by the novel robust optimization model, our models results are compared to those generated by the chance-constrained programming model under the data of STAM SANAT Company. Further, the advantages of using this integrated approach versus a sequential approach under currency fluctuations are shown.
Keywords: Supplier selection; Lot-size; Transportation mode selection; Robust programming; Discount; Currency exchange rate uncertainty.
Operational behaviour of a clarifier system in the sugar industry using supplementary variable technique
by Ramesh Kumar, M.S. Kadyan
Abstract: In this paper, the clarifier system in the sugar industry is analysed that having three subsystems- Raw juice heater, Juice sulphitor and Sulphited juice heater. These subsystems are arranged in series. Both the subsystems Raw juice heater and Sulphited juice heater have standby unit whereas subsystem Juice sulphitor has single unit. The time to failure of the subsystems follows negative exponential distribution while repair time distribution is taken as arbitrary. The differential-difference equations associated with the state changeover model are developed by using supplementary variable technique and these equations are solved to get state probabilities of the system model. A particular case is also considered to show the behaviour of availability and expected profit of the clarifier system in the sugar industry.
Keywords: availability; clarifier system; expected profit; sugar industry; supplementary variable technique.
Performance Analysis of a FLP Problem using AHP-TOPSIS and FAHP-FTOPSIS
by Divya Agarwal, Ajay K.S. Singholi
Abstract: To meet the ever-increasing demands of manufactured product and rising competition among rival industries; well-organized, inexpensive, efficient and effective facility layout plan (FLP) needs to be equipped. FLP decision problem entails to assignment of departments, positioning of machine equipments, material handling decisions, design as well as planning of production operations, required for higher productivity with better quality and improved efficiency. It is estimated that 70% of the total production cost is due to material handling (including equipments, direct-indirect labor costs, etc.), within a facility layout however, better facility placement can contribute to up to 30% less operating expenses. ABC Pvt. Limited was considered for FLP problem because of improper material flow through shop floor and extended transportation time for material transfer. The objective of this research is to analyze and compare the performance of existing Front Axle Division Layout of ABC Pvt. Limited with the four proposed design alternatives using AHP-TOPSIS and FAHP-FTOPSIS, thereby reducing production time, material handling distance and material handling cost (MHC). The management of the case study company has adopted the analysis results as the basis to their future layout planning problem. The practical contribution of this research can, thus, be justified.
Keywords: Facility Layout; Analytical Hierarchical Process (AHP);Fuzzy AHP (FAHP); Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS); Fuzzy TOPSIS (FTOPSIS); Material Handling; Multiple Criteria Decision Making Problem (MCDM).
The New Ranking method of the Decision Making Units in DEA: with an Approach to Modifying the Cross Efficiency method.
by Behzad Paryzad
Abstract: There is no doubt that organizations need an operation evaluation and measurement for having more efficiency and an optimal usage of their limited sources. One of the most practical methods for evaluating the operation is using the data envelopment analysis. Hence, DEA (Data Envelopment Analysis) and ranking DMU (Decision Making Units) are the most favorite subjects for the researchers. This method has modified on a different style on this article that has removed the existence of multiple optimal answers in the CCR (Chames-Cooper and Rhodes). In other words, the acquired ranks of the units are particular and have achieved with a special delicacy. In order to show the efficiencies of the method, some examples have presented that had achieved the more desirable and accurate ranking. The calculated results of performing this method have compared with the Anderson-Peterson method and its flexibility has studied according to the ANOVA (Analysis of Variance).
Keywords: Cross Efficiency; New ranking method; DEA; ANOVA.
A state-of-the-art literature survey of grey relational analysis(GRA)applications in competitive business environment
by Arvind Jayant, Vikrant Giri, Pradeep K. Singh, Sunil Luthra
Abstract: Multi-Criteria Decision Making (MCDM) approaches have been accepted a significant consideration from scientists and professionals for evaluating, surveying and selecting best alternatives for different commercial enterprises (production industries, e-commerce providers and many more). Out of various MCDM approaches developed to unravel real-world decision making problems, Grey Relational Analysis (GRA) keeps on working satisfactorily over diversified fields of business. In this paper, we conduct a state-of-the-art literature survey to taxonomize the research on GRA applications and methodologies in competitive business environment. The present paper is classified into five fields of applications viz. Supply chain and logistics management, manufacturing systems and design engineering, management and business, energy and environment management and some other areas of application. Research papers on GRA requisitions are again distributed based on number of publications in consecutive years and other methodologies compared or coordinated with GRA. We concluded our review paper with recommendations for future research directions in GRA decision-making that is both forward-looking and practically oriented. This paper provides useful insights into the GRA based decision making applications in the real business world and suggests a framework for future attempts in this area for academic researchers and industry practitioners. Keywords: Grey Relational Analysis (GRA), Supply Chain Management (SCM), Environment management, Multi-Criteria Decision Making (MCDM).
Keywords: Grey Relational Analysis (GRA); Supply Chain Management (SCM); Environment management; Multi-Criteria Decision Making (MCDM).
Cloud Based Manufacturing Execution System: Case Study FMS
by Ali Vatankhah Barenji
Abstract: In this paper, the needs and challenges confronted by the IT infrastructure of Small and Medium Sized enterprises (SMEs) was analyzed. The findings showed that the needs and challenges in data integration within the SMEs network affects the complexity of the IT system as well as the communication between the enterprise resource planning(ERP) and manufacturing execution system(MES), resulting in the lack of real time delivery. In other to cover the gaps between MES and ERP, this paper proposed a cloud based MES (CbMES); to develop the CbMES, a framework based on the model driven architecture (MDA) was used. This framework is a step-by-step framework for developing CbMES. For evaluating the proposed system, a flexible manufacturing system is selected as the case study. The proposed CbMES is developed for flexible manufacturing system and has been implemented within the oracle cloud platform, for the evaluation of this system, a simulation platform based on the color petri net is utilized. The result of simulation indicates that the proposed CbMAS is capable of closing the gaps between MES and ERP; therefore, the outcome of the results showed that the uptime productivity and the production rate of flexible manufacturing systems increased considerably meaning that the system is an effective and viable solution for the IT infrastructure.
Keywords: ERP; MES; Model Driven Architecture; Software as a Service; Cloud Computing.
Risk Assessment Modelling for Power Optical Backbone Communication Network based on MLFSR-oriented Sampling Markov Technique
by Huisheng Gao, Yujun He
Abstract: Considering the large-scale power optical backbone communication network with diverse link failure statuses and complicated service configuration modes, a hybrid multi-link failure statuses reduction (MLFSR)-oriented Sampling Markov technique used for network service risk assessment is proposed. First, the multi-link failure events, statuses and Markov model have been introduced for power communication network. Second, the link failure probability p is determined through link failure rate λ and repair rate μ. Then the link failure statuses can be reduced according to p, links number n and confidence level α;, which simplifies the failure state Markov model with less calculation work in assessing the possible service loss. Third, for certain reduced valid link failure status, there are also a large number of failure events. Considering the sampling accuracy, the sample size (i.e. failure events) for each link failure status can be further reduced based on t bilateral percentile statistic theory, resulting in less calculation in service loss estimation. Finally, the concrete risk assessment procedures of the proposed method are described, and the simulation and comparison analysis are carried out for a practical communication network to test the feasibility and validity of the proposed method. The results show that the network risk R has approximate linear relationship with the link failure rate λ and the mean repair time τ. This study is expected to be of significant reference value for formulating risk-controlling measures to diminish communication network risk for operation departments.
Keywords: power communication network; optical backbone network; link failure status reduction; service risk.
A Multi-objective Programming Model for Selection Third-Party Logistics Companies and Suppliers in a Closed-loop Supply Chain
by Hashem Omrani, Iman Hushyar, Saman Moradi Zolmabadi, Abolfazl Jafari Asl
Abstract: Due to globalization and increasing competition in markets, the manufacturers and service organizations tend to outsource their logistics activities. On behalf of manufacturers and service organizations, an outer firm which called third party logistics (3PLs) company manages, controls and performs the logistics activities. In this paper, a general closed-loop supply chain network is designed that includes manufacturers, third party logistics (3PLs), supplier, evaluation, disassembly, refurbishing and disposal sites. The proposed model of this paper has two phases. First phase determines 3PL and external supplier by using fuzzy sets theory. Namely, the preferences of decision makers for selecting 3PLs and suppliers are expressed by triangular fuzzy numbers and then, the weights of 3PLs and suppliers are determined. In the second phase, a multi-objective mixed integer linear programming model is proposed to determine the product optimum quantity assigned to the 3PL and parts purchased from supplier. The proposed model considers 3PL and supplier selection, simultaneously. To illustrate the capability of the suggested model, a numerical example is solved and the results are analyzed.
Keywords: Supply chain management; Reverse logistic; Suppliers selection; Third party logistic (3PL); Mixed integer linear programming; Fuzzy logic.
Investigating the application of meta-heuristic algorithms in optimizing opportunistic maintenance: an exploratory study
by Arash Shahin, Saeede Jokar
Abstract: Opportunistic maintenance is very effective in optimizing the existing costs of production. The aim of this article is to optimize opportunistic maintenance. For this purpose, based on an example, various methods such as genetic algorithm, imperialist competition algorithm, simulated annealing algorithm, artificial bee colony algorithm and particle swarm algorithm have been considered for solving the problem and the approaches have been compared to find the most cost effective approach. Findings imply that the imperialist competition algorithm is the most suitable solution.
Keywords: Opportunistic Maintenance; Optimization; Imperialist Competition Algorithm; Simulated Annealing Algorithm; Genetic Algorithm; Artificial Bees Colony Algorithm; Particle Swarm Algorithm.
Analysis on the characteristics for a new differential crawling device of an insulator inspection robot
by Xiaopeng Li, Wujiu Pan, Shujun Li, Hongguang Wang
Abstract: In order to realize the synchronous drive of the insulator inspection robot with a simple control system, a single drive crawling device of the robot is designed. This device has a three-degree freedom (3-DOF) differential drive system which can be driven by a motor to make the three sets of arm crawl synchronously. It has a certain ability of self-adaption and compensating output errors. First, the crawling devices assembly model of insulator inspection robot is designed which includes three main components：crawling arms, driving mechanism and guiding mechanism. Then the kinematics analysis is established. In addition, a kineto-statics model is founded to analyse the total torque and the stress state of the contact points when the device is crawling. Finally, simulation is used to analyse and the error adjustment of crawling device is studied. After theoretical analysis and dynamic simulation of the crawling device, results show that it has a certain ability of error adjustment and will run normally when there is an oblique angle error with the suspension insulator strings.
Keywords: insulator; inspection robot; differential drive; crawling device; error self-adjustment.
Robust Integral Backstepping Control with Extended Kalman Filter of Permanent Magnet Synchronous Motor
by Bassema Bakhti
Abstract: Sensorless integral Backstepping control combined with Extended Kalman Filter applied to permanent magnet synchronous motors (PMSM) is the topic of this paper. Moreover, a robust Backstepping control is designed where an integral action is introduced in order to improve the robust properties of the controller.Our proposed control strategy is based on an accurate extended Kalman filter observer that estimates speed, position, stator currents and load torque. This Kalman filter is an optimal state estimator and is usually applied to a dynamic system that involves a random noise environment. The stability of the system with the observer controller scheme is analyzed and sufficient conditions are given to prove the practical stability. Simulation results are shown to illustrate the performance of the proposed scheme under parametric uncertainties and low speed.
Keywords: Permanent magnet synchronous motor; PMSM; Sensorless control; integral Backstepping control;I-Back; Extended Kalman filter; EKF.
Exploring the Relationship of Discrete Components of Inventory with Financial Performance in Indian Automotive Industry
by Tanuj Nandan, Vikas Kumar Choubey
Abstract: Inventory holdings and its discrete components [i.e. Raw Materials Inventory (RMI), Work in Process Inventory (WIPI) and Finished Goods Inventory (FGI)] are very important factors influencing the firm performance. The objective of this paper is to study the relationship between discrete components of inventory (raw material (RM), work-in-process (WIP), and finished goods (FG)), and financial performance in manufacturing companies. Statistical analysis has been applied to the financial information of 522 Indian automotive manufacturing firms over the 10-year period from 2002-03 to 2011-12. Through the analysis, this paper finds statistically significant relationships between the discrete components of inventory and measures of financial performance (at both the gross and operating levels) for firms in automotive manufacturing industries. This paper adds to previous literature by discussing and testing the relationship between the discrete types of inventory (RMI, WIPI, and FGI) and firms profitability of operations, both at the gross and at the operating profit levels.
Keywords: Discrete components of Inventory; Financial performance; Operational efficiency; Automotive manufacturing industries.
Statistical Study on the use of the measurement techniques in predictive maintenance taking Moroccan companies as an example
by Amal BOUKILI, Mohammed EL HAMMOUMI, Said HAOUACHE
Abstract: This article presents where Moroccan companies stand the use of the measurement techniques in predictive maintenance. The objective is to identify the main advantages and disadvantages of each measurement technique (vibratory analysis; thermography; radiography; penetrant testing; magnetoscopy and ultrasonic) taking into account the characteristics of the production (continuous, discontinuous, by project) and the sector of activity (agri-food, automobile, textile, service sector...).
This survey allows determining how many Moroccan industries use measurement techniques to avoid breakage that could slow down and even stop producing a preventive maintenance program.
It brings the original data on the choice of a technique among others considering the nature of the physical monitoring parameter and criteria of speed, cost, reproducibility, reliability, sensitivity and resolution of each measurement technique.
As a result, the industrial managers may rely on the results of this survey in order to use a maintenance program directed to a predictive maintenance. The most suitable technique should be chosen, taking into consideration the field of activity of each company and based on the advantages and disadvantages of each measurement technique.
Keywords: preventive maintenance; vibratory analysis; thermography; radiography; penetrant testing; magnetoscopy and ultrasonic; speed; cost; reproducibility; reliability; sensitivity and resolution.
Assessing Software Upgradation Attributes & Optimal Release Planning Using DEMATEL & MAUT
by Rana Majumdar, P.K. Kapur, Sunil.K. Khatri
Abstract: This study analyzes the software upgradations aspects of industries by applying the Decision Making Trial and Evaluation Laboratory (DEMATEL) method and then finding the Optimal Release Time of the Upgraded software using Multi Attribute Utility Theory (MAUT) to remain competitive in the market. The software developers are trying very hard to mark their presence by offering new functionalities in the software within defined time frame. Founded on the literature reviews and based on experts opinion, three significant viewpoints and eight attribute were identified as Key factors and then further confirmed by industry professionals. In the process of confirmation/validation a survey was conducted, professionals expressed their views based on questionnaires. DEMATEL method used for attribute analysis and finally casual relations among the attribute were shaped. The result exhibited that the strategic perception from management point of view was the most significant perception and greatly influenced the remaining two viewpoints. The applicability of DEMATEL method is to confirm interrelationships among diverse attributes and helps to recognize the key attributes whereas the role of MAUT process is to identify the release time of Software based on casual relations among attributes. This work orients itself by identifying different attributes for software upgradations and then related attributes are listed under key viewpoints. The causal model identifies the main causes and effects and also specifies priorities of each attributes. By using the influenced-influencing matrix, key factors were identified. We examined the proposed technique on primary data collected from IT companies and obtained significant results that provides for far greater insights into upgradation attributes than existing processes. During the process of applying DEMATEL & MAUT, panel of experts plays a balancing and support role for software upgradations and release time planning. So here the objective is twofold. i) To identify and analyze upgradation attributes ii) Based on analysis/outcome of DEMATEL method optimal release time of software is determined
Keywords: Decision Making Trial and Evaluation Laboratory; Cause and effect relationship; Multi Attribute Utility Theory.
Reliability Evaluation and Improvement of Manufacturing Helicopter in an Aircraft Manufacturing Company Case Study: Skid Types Helicopter Landing Gear
by Mohammad Farahmand, Maliheh Ganji, Seyed Mojtaba Sajadi
Abstract: Due to its sensitivity to time and accuracy, aerospace equipment requires a highly accurate manufacturing process to achieve higher reliability compared to other equipment. Focusing the studied helicopter, this study examines reliability of components of a landing gear manufactured by an aircraft company to improve total reliability of the product. Developing a model for risk-based design of a landing gear, this study proposes an inclusive approach for evaluating and promoting total reliability of the landing gear. This study identifies different components of a product to examine reliability of a component of that product. Then, the components are prioritized by FMEA for promotion to increase total reliability of the product. In conclusion, the objective of this study is to develop an inclusive model for improving reliability of mechanical components of landing gear manufactured by an aircraft company.
Keywords: Reliability;Feasibility of Objectives (FOO); Fault Tree Analysis (FTA); Failure Modes and Effects Analysis (FMEA); Helicopter Landing Gear.
One vendor and multiple retailers system in vendor managed inventory problem with stochastic demand
by Cahyono Sigit Pramudyo, Huynh Trung Luong
Abstract: In many supply networks, the retailers are reluctant to share information about demand and inventory level to the vendor. This might lead to many difficulties for the vendor in establishing his own order/production plan. Vendor managed inventory (VMI) policy can help to solve that problem. By applying VMI, information sharing is not really a problem for the vendor anymore and this policy have been proven to help reduce total inventory cost as well as improve customer service level in the supply network. In this research, a VMI model for the system with one vendor and multiple retailers will be developed. The main target of the model is to determine the retailers lot size, the vendors lot size, the retailer cycle time, and the number of replenishments in a vendor cycle so as to minimize the total system cost. For solution purpose, simulation-optimization technique using genetic algorithm is employed to help find optimal solutions for the decision variables. Numerical experiments are conducted to show the applicability of the proposed model. Sensitivity analysis is also conducted to examine the effects of some input parameters on the optimal solution.
Keywords: Vendor managed inventory; genetic algorithm; stochastic demand.
Improving Dual Importance Analysis Based on A Shapley Value Associated with A Fuzzy Measure When Interactions of Criteria are Significant
by Jiunn-I Shieh, Hsin-Hung Wu
Abstract: Kano model is very useful to classify customer needs into different categories by completely using self-stated evaluations. The disadvantages of using self-stated evaluation are respondents often find it difficult to differentiate and respondents answers may be influenced by social norms or political correctness. In contrast, the derived evaluation approach uses a less direct way of uncovering the evaluations that are most reliable to reflect the respondents view from the survey. Multiple regression, structural equation modeling, partial correlation, or generalized correlations commonly used in the derived importance are all based on weak interaction assumption among items. However, an interaction effect particularly non-linear interaction is often incurred in practice. To overcome this major drawback, a framework of using the dual importance graph with self-stated performance and derived importance to classify the service items into different types of Kanos categories is proposed. The derived importance was computed by a Shapley value associated with a fuzzy measure method to deal with significant interactions among items by further considering both linear and non-linear effects instead of solely considering and assuming linear effects. A case of evaluating the service quality of a particular hospital is illustrated to show how this proposed framework works to classify the service items into different types of Kanos categories. The result shows that using the Shapley value-based dual importance graph is more practical to deal with interactions of items.
Keywords: Kano’s model; dual importance diagram; Shannon interaction information; fuzzy measure; Shapley value.
An integrated analytical framework based on fuzzy DEMATEL and fuzzy ANP for competitive market strategy selection
by Mohamad H. Gholami
Abstract: Selection of an appropriate competitive market strategy is inevitable for firms to create value for customers and consequently to achieve competitive advantage over their competitors. However, selection of such strategy is not straightforward at all because it requires considering numerous factors including internal and external factors that affect the firms performance and assessing the complex relationships between them. The current study considers the selection of the best competitive market strategy as a multiple criteria decision making problem and proposes an integrated framework on the basis of the resource-based view (RBV) of the firm as internal factors (firm-level analysis) and Porters competitive forces as external factors (industry-level analysis). The aim of the current study is to propose a systematic decision support framework integrating the RBV of the firm and Porters industry analysis to select the best competitive market strategy that can enhance the competitive advantage of a firm. The suggested framework utilizes fuzzy decision making trial and evaluation laboratory (fuzzy DEMATEL) and fuzzy analytic network process (fuzzy ANP) in both firm-level and industry-level analyses to obtain the causal relationships between criteria and to solve the networks, respectively. Also, the discussion on how to provide a settlement between the two analyses is presented. Furthermore, to demonstrate the application of the developed framework, an empirical example from insurance industry is provided.
Keywords: Competitive market strategy; Resource-based view (RBV); Porter’s competitive forces; Porter’s generic strategies; Fuzzy decision making trial and evaluation laboratory (fuzzy DEMATEL); Fuzzy analytic network process (fuzzy ANP).
A multi-objective modeling approach to assess the impact of maintenance scheduling on equipment procurement methods
by Ali Sayyah, Reza Baradaran Kazemzadeh, Mohammad Mehdi Sepehri, Hamidreza Eskandari
Abstract: In this research, a new multi-objective optimization model is developed from equipment users point of view who is seeking to select from among the buy/lease/upgrade decisions and maintenance schedule options when the equipment performance criteria and total cost are in consideration. The proposed model determines the possible non-dominated physical asset management (AM) strategies by interconnecting procurement parameters, maintenance scheduling variables, and equipments working historical data. Total operational cost, the equipment reliability and unavailability are the objectives of the model which is solved using NSGA-II. Each of the achieved strategies consists of a procurement method (buy/lease/upgrade) and a maintenance strategy (PM degree, PM interval and upgrade level). The model is applied to a specific equipment to determine non-dominated asset management strategies for a specified time horizon in a copper mine. The results show that by managing maintenance variables, the decision maker is capable of choosing a proper procurement strategy to the organization from among various equivalent AM strategies.
Keywords: Maintenance Scheduling; Multi-objective Optimization; Equipment Procurement; Physical Asset Management; Reliability; Unavailability; NSGA-II.
A Resilient Supply Portfolio Considering Political and Disruption Risks
by Reza Hosnavi, Mohammad Ali Nekooie, Seyed Mohammad Khalili, Ahmad Tavakoli
Abstract: The need of accounting for resilience in global supply chains has been growing from practical and academic points of view. However, there is still the need for developing quantitative decision support models on this issue. In the present work we propose a novel multi-objective mixed possibilistic, two-stage scenario-based stochastic programming model to handle supplier selection and order allocation problem in a global supply chain under operational and disruption risks. The model minimizes cost and political risk, whilst, maximizes resilience of the supply portfolio. Various risk mitigation approaches including: contracting with backup suppliers, fortification of suppliers and procurement of emergency inventory, are considered in the model. In addition, the proposed model determines recovery plan. Reservation Level driven Tchebycheff Procedure is incorporated in the solution procedure to find Pareto-optimal solutions. The validation of the model via computational experiments demonstrate the applicability of the proposed model and solution method in building a resilient supply portfolio under consideration of operational and disruption risks.
Keywords: supply chain risk/disruption management; resilient supply portfolio; mixed possibilistic two-stage stochastic programming.
Quality Management Practices and Sustainable Performance: Examining the Role of Soft TQM as Mediator
by Amjad Khalili, Md Yusof Ismail, A.N.Mustafizul Karim, Mohd Radzi Che Daud
Abstract: Malaysian managers are trying to implement Quality Management (QM) practices in their industries to be competitive. However, minute empirical studies are conducted in the developing economy of Malaysia to examine the role of TQM soft dimension (STQM) as possible mediator in the relationship among QMS ISO 9001:2015 and Sustainable Performance (SP). Exhausting 329 primary data collected from Malaysian numerous industries; this paper aims to develop a conceptual model that links the three practices namely QMS, STQM and SP in one integrated model and to examine the mediating structure of Soft TQM (STQM) aspects through techniques exploited from Structural Equation Modeling (SEM). Findings from AMOS program show that Bootstrapping technique supported that STQM is treated as mediator construct. Though, full mediation is detected in this paper which reflects the importance of practicing STQM aspects for Malaysian manufacturers. The main contribution of this paper is through introducing bootstrapping for mediating estimation and focusing on all measured industrial sector in Malaysia needs to be an industrialized nation in the coming few years.
Keywords: QMS; Soft TQM; Sustainable; Mediating; Bootstrapping; Malaysia.
Analysing Salesmen Itinerary with Agglomerative Hierarchical Clustering & Vehicle Routing Algorithm - a case study of a confectionery supplier in Indonesia
by Elia Oey, M. Idham Sofyan, Alexander Batara Marpaung
Abstract: The study analysed salesmen itinerary of a confectionery supplier in Indonesia. Channel management and robust product distribution are important elements for confectionery business, since growth heavily depends on healthy product distribution. To support product distribution, optimizing salesmen itinerary plays an important role in the firms sales operation. The study was limited to optimizing salesmen schedule for its wholesalers outlet type, since it contributed to 78% of its revenue. The analyses were carried out using cluster first-route second approach. For clustering the customer nodes, it recommended agglomerative hierarchical clustering (AHC) method. For routing within each customers cluster, it tested two algorithms, i.e. Clarke-Wright and Weighted-Serving Time-Visual approach. The result showed that AHC-Weighted-Serving-Time-Visual algorithm was as good as AHC-Clarke-Wright with 2.1% cheaper variable cost. The proposed algorithm was adapted from practical insight and easier to be understood.
Keywords: Cluster first-route second; Vehicle Routing Problem (VRP); Agglomerative Hierarchical Clustering (AHC); Clarke-Wright; Weighted-Serving Time-Visual approach.
Managing Cost of Quality in Supply Chain: A Case Study
by Amiya Pattanayak, Anand Prakash, Rajendra Mohanty
Abstract: This paper attempts to present the overseeing situation of cost of quality (CoQ) in the supply chain of an integrated aluminium manufacturing company as the case example shown by the authors. The study has critiqued a wide range of published literature to provide an indepth review of CoQ and CoQ in the supply chain. This study describes an application of grounded theory approach for CoQ in the supply chain to demonstrate what can be found and how the information on CoQ in supply chain of the case example can help. The study considers rigorous methodological usefulness of the research results to benefit researchers and practitioners in making financial improvements, with justification in planning and controlling of quality in the supply chain. This study explains that CoQ in the supply chain helps in realising there is a sustainable competitive advantage through its proficient know-how advancement founded on internal analysis under conditions of uncertainty, complexity and conflicts.
Keywords: Cost of Quality; Grounded Theory; Management; Quality; Quality Cost; Supply Chain.
Evaluation of reliability, availability and maintainability of a milk production line
by Panagiotis Tsarouhas
Abstract: The application of statistical approaches of failure data for analyzing the reliability, availability and maintainability of a milk production line were carried out. Descriptive statistics of the failure and repair data was computed and the best fitness indexes were determined. The parameters of some idealized probability distributions, such as Weibull, Exponential, Lognormal, and normal distributions have been estimated. Reliability and maintainability (R&M) of workstation and the entire line at different mission times with their best fit distribution have been estimated. Both R&M proved to be useful tools to assess the current situation, and to predict reliability, mainly in short term, for upgrading the operation management of the milk production line. It was pointed out that: (a) the availability for the milk production line was 96.13% and the line was down or under repair for 3.9%. (b) Both bottling machine and heat exchanger/pasteurizer machine had 57.5% of all the failures that presented on the production line, and (c) there were no-trend and serial correlation for both failure and repair data. The records of failures and repairs can be a useful database for manufacturers of milk industry to design new reliable and safe equipment.
Keywords: Reliability; maintainability; performance evaluation; field failure/repair data.
An Integrated AHPDEA methodology for Evaluation and Ranking of Production Methods in Industrial Environments
by Saeideh Naghiha, Reza Maddahi, Ali Ebrahimnejad
Abstract: Decision making about the superior method to produce products is essential to growth and dynamism of productive organizations. In this regard, utilizing a model to evaluate the comprehensive performance of different manufacturing methods is significant. In addition, defining and finding the suitable indexes of decision making is required to the proper implementation of performance evaluation system. Thus, in this study, it is attempted to select the best production method and to supply material using Data Envelopment Analysis (DEA) technique and analytic hierarchy process (AHP). In this regard, the performance of Ball valve production in Petro Nab Sepahan Manufacturing Company is assessed and ranked using these two methods by considering dimensions such as quality, cost, and function as well as acquired measures.
Keywords: Performance assessment; Efficiency; Analytic hierarchy process (AHP); Data Envelopment Analysis (DEA); Ball valve.
Warranty Cost Sharing Policies with Preventive Maintenance Strategy for Sensor Embedded Remanufactured Products
by Ammar Alqahtani, Surendra Gupta
Abstract: With the recent surge of technological development and consumer preference to purchase newer device models and technological products, product life cycles have diminished and disposal rates have spiked. As a result, landfills and the Earths natural resources have begun to reach a critical apex. In response to this apex, when a technological device reaches the end of its life cycle, and it becomes obsolete, manufacturing firms now repossess the products they produced. Manufacturers attempt to respond to consumers concerns involving environmental issues as well as the more governmentally stringent environmental legislations by establishing facilities which include the minimization of the totality of waste relocated to landfills by recovering materials and components from returned, or End-Of-Life (EOL) products and reuse them to build a remanufactured product, and/or novel components. With the rapid growth of interest in remanufactured products market, offering warranty for remanufactured products and components is becoming a necessity for remanufacturer in order to meet customers requirement and as a marketing mechanism. During that process, maintenance policies are of great importance in order to reduce the warranty cost on the remanufacturer. In this paper, an optimization simulation model for remanufactured items sold with one-dimensional non-renewing Cost Sharing Warranty (CSW) and Cost Limit Warranty (CLW) are proposed from the view of remanufacturer. In which, an End-Of-Life product (EOLP) is subjected to upgrade action at the end of its past life and during the warranty period, preventive maintenance actions are carried out when the remaining life of the product reaches a pre-specified value so that the remanufacturers expected profit can be maximized. Finally, a numerical example and Design of Experiment analysis are provided to demonstrate the proposed approach.
Keywords: Reverse Supply Chain; Preventive Maintenance; Warranty Policies; Remanufacturing; Sensor Embedded Products.
A precise direct parametric interpolation method for NURBS-toolpath generation
by De-ning Song, Zhen-yuan Jia, Jian-wei Ma, Ning Zhang, Li-kun Si
Abstract: Non-uniform rational B-spline (NURBS) interpolator has many advantages over conventional linear/circular interpolator. However, as there is a nonlinear corresponding relation between the curve parameter and the arc displacement of the NURBS curve, it is hard to accurately calculate the parameter of the next interpolation point, thus resulting in a deviation between the desired and the actual feedrate, i.e. feedrate fluctuation. A large feedrate fluctuation may cause the machine-tool vibration, which is bad for the cutter life and the machining quality. Therefore, aiming at reducing the feedrate fluctuation, this paper presents a high-precision parametric interpolation method, which features a second-order Runge-Kutta algorithm with parameter compensation. First, a second-order Runge-Kutta method is employed to compute the initial interpolation-point parameter. After that, the parameter is compensated using first-order Taylors expansion of the feedrate-fluctuation function, thus enhancing the calculation precision of the next-interpolation-point parameter. Experimental results demonstrate the advantage of the presented method.
Keywords: Parametric interpolation; NURBS interpolator; Feedrate fluctuation; High-precision machining.
An active observer based predictive energy management strategy for engine waste heat recovery system
by Zhengling Lei, Hui Xie
Abstract: In this paper, energy management of waste heat recovery system has been attacked based on a three-steps problem formulation approach. The problem has been formulated into a bilevel programme, where the upper level is designed to optimise the usage of recovered energy and the lower level is arranged to maximise the recovered energy. However, detailed models for real-time decision-making cannot be easily obtained. In order to ensure the energy management performance, an active observer named extended state observer is adopted to compensate for static models via online information of the real energy network. The final decision-making of the energy management is conducted based on the reconstructed model, which is simpler and more accurate. An energy network constructed by -----is employed as the research object. Simulation study conducted by GT-SUITE software is used to verify the sub-goals of the problem configuration, including model self-reconstruction capability and fuel-saving potential. For two given testing cycles, simulation results indicate fairly good self-reconstruction capability can be ensured, while considerable fuel-saving capability can be reached comparing with a baseline strategy, indicating the effectiveness of the proposed approach.
Keywords: engine waste heat recovery; extended state observer; bilevel programming; energy management.
Simulated annealing algorithms to minimize the completion time variance of jobs in permutation flowshops
by J. Krishnaraj, S. Pugazhendhi, Chandrasekharan Rajendran, S. Thiagarajan
Abstract: In this paper, the permutation flowshop scheduling problem with the objective of minimizing the completion time variance (CTV) of jobs is considered, and a simulated annealing algorithm (SA) and two modified SAs (MSA1 and MSA2) are proposed. In the first phase, the proposed algorithms are used to minimize CTV of jobs without any right shifting of completion times of jobs on the last machine (RSCT). As followed in the literature some times, the RSCT (except that of the last job) is attempted in the second phase, and in the third phase, we convert sequences so as to follow the V-shaped property with respect to processing time of jobs on the last machine, followed by RSCT except that of the last job, so that the makespan and the machine utilization in the shop floor remain the same. We present an extensive computational evaluation of the existing and the proposed heuristic algorithms.
Keywords: Scheduling; Permutation flowshop; Simulated annealing algorithm; Completion time variance.
An Application of Routing Location and Allocation Model for Drinking Water Distribution
by Armagan Bayram, Senay Solak
Abstract: Due to severe droughts occurring in southwest China, this region is facing a perilous water crisis for a long time. To meet the daily drinking water demand, the government is sending water to these rural areas via trucks. This study addresses a type of vehicle routing problem motivated by a drinking water distribution application (via trucks) in Luxi County, China to help alleviate the drought in this region. A specific characteristic of this application is that the vehicle routing problem is integrated with facility location and allocation problems. We model this problem as a mixed-integer program where the objective involves the minimization of a weighted function of efficiency (i.e. vehicle transportation costs) and equity (i.e. village assignment costs) metrics. Due to the computational complexity of the integer programming model, two heuristic approaches are proposed to obtain more efficient and practical solutions. Through our heuristics, we split the problem into the routing and location-allocation models and solve them sequentially. We further propose Benders decomposition algorithm and perform computational analysis to compare the efficiency of mixed integer programming model, heuristic approaches and Benders decomposition algorithm by using realistically generated instances. Through our computational analysis, we also explore how different objective metrics influence the distribution of drinking water.
Keywords: Vehicle routing and allocation; nonprofit vehicle routing; mixed-integer programming; resource allocation; water distribution.
A robust optimization model for sustainable blood supply chain network design under uncertainty
by Zahra Mohammadian, Armin Jabbarzadeh, Mir Saman Pishvaee
Abstract: Blood is a perishable, scarce and lifesaving product. While the demand for blood products has been increased over the past few decades, there has been no specified artificial alternative for this critical product yet. In this context, it is of paramount importance to design efficient, agile and effective blood supply chain networks. This paper presents a multi-objective stochastic programming model for blood supply chain network design by considering the following objectives: minimizing total cost, minimizing delivery time, and maximizing two important social measures including the indicator of consumers health and the rate of regular blood donors. A robust optimization approach is employed to incorporate different sources of uncertainties in demand and supply parameters. To investigate the performance and utility of the proposed formulation, the model is implemented using real data of blood transfusion network of Tehran.
Keywords: Blood supply chain; Network design; Sustainability; Uncertainty; ɛ-constraint method.
Experimentation and Weld Parameter Optimization using Grey Fuzzy analysis
by Satheesh Moni, Edwin John
Abstract: The most popular steel grade material highly used in the fabrication of industrial pressure vessels and boilers is SA516 Grade 70. Submerged Arc Welding is a metal joining technique widely used in heavy fabrication industries for its high quality, reliability, attaining deeper penetration and a smooth appearance of weld bead. In this paper, Taguchis L27 orthogonal array is used to perform welding of SA 516 grade 70 steel plates. To improve the weld quality, the optimal combination of welding parameters is chosen using grey relational analysis. Grey fuzzy optimization of welding parameters is based on four different output performance characteristics, namely, bead reinforcement, bead width, bead penetration and dilution. From Analysis of variance it is evident that electrode stickout is the most influential factor in submerged arc welding process parameters. Mechanical and metallurgical studies are performed to confirm the effectiveness of the approach.
Keywords: ANOVA; Bead geometry; Orthogonal array; Taguchi method;Fuzzy.
Analysis of Machine-Repairing Systems with Server Breakdown and Delayed Repairs
by Jau-Chuan Ke, Tzu-Hsin Liu, Ying-Lin Hsu, Hui-Tzu Ku
Abstract: This paper considers a machine-repairing system with a partial breakdown and delay-repairs. When the servers fail, the service continues at a slower rate instead of stopping completely. We utilize a matrix-analytic method to obtain steady-state solutions. We then develop system performance measures. A cost model is developed to simultaneously determine the optimal value of the number of servers, the number of standby servers, the two service rates, and the cost of maintaining system availability at an acceptable level. We employ the probabilistic global search Lausanne method to deal with the optimization problem. Sensitivity analysis is also conducted in which various system parameters are evaluated under optimal operating conditions. Finally, an application example is provided to demonstrate how the presented model could be used in real-life situations.
Keywords: cost analysis; partial breakdowns; delayed repairs; warm standby machine; probabilistic global search Lausanne.
Reducing Barriers to the Implementation of Strategic Management by Providing Improved Strategies: Using Fuzzy QFD applied to Petropars Company
by Daryosh Mohamadijanaki, Abolfazl Mirzazadeh, Mehdi Mohamadijanaki
Abstract: In all organizations, the transition from strategy development to strategy implementation requires a change in responsibilities. Petropars has been chosen as a real case in the oil and gas industry. In this research, we have tried to address the fundamental problems of private companies in implementing strategic management, And in interviews with the top managers and experts of Petro Pars Company, some of the main barriers to implementation of strategic management were identified. In this paper, a quality-performance-based approach is proposed. Using the fuzzy method, different parts of the house of quality, and the relationship of the stakeholders' desire to improve barriers, are removed from linguistic and ambiguous strategies with strategic actions, How to use both the house of quality (HOQ) and fuzzy logic, and adding four new fuzzy parts to the quality house, and finally, using the quality home, the transformation of barriers to implementing strategic management to the improvement strategies is presented in Table 12.
Keywords: Fuzzy QFD; strategic management Obstacles; Petropars ,stakeholders.
Research on Static Friction Coefficient of Joint Surfaces Considering Elastic-plastic Deformation Based on Fractal Model
by Xiaopeng Li, Ze Wang
Abstract: In order to study the influence of the microscopic morphology on joint surfaces, it is necessary to consider the elastic-plastic deformation of micro-bulge. Based on the M-B fractal model, the mathematical equation of normal and tangential load of elastic-plastic deformation is obtained. Then, contact fractal models of static friction coefficient with the elastic-plastic deformation considered and not considered are established respectively. Two models have geometric characteristics and scale independence. The contact fractal model of static friction coefficient considering elastic-plastic deformation is analyzed by changing different characteristic parameters. And the nonlinear relationships between static friction coefficient and characteristic parameters of joint surfaces are revealed. The results show that the static friction coefficient is increased with the normal load and material parameters increase. While the static friction coefficient is decreased with the fractal scale parameters increase. And the relationship between the static friction coefficient and fractal dimensions is complex. When 1.1 Keywords: joint surfaces; elastic-plastic deformation; static friction coefficient; fractal theory; the nonlinear relationships.
Effect of individual and work parameters on musculoskeletal health of manual agriculture workers
by R. Jain
Abstract: Musculoskeletal disorders (MSDs) are a major work-related issue for farmers. The aim of this cross-sectional study to find out the occurrence and risk factors for MSDs in the manual agriculture workers. A sample of Indian workers was surveyed (N = 138). An information theory method was investigated to determine the comparative feature of mathematical models for a specified group of data collected on MSDs, individual and work parameters. The result from the AIC analysis used further to select a model of the extreme fit. Risk Factors associated with MSDs in the final model with 95% bootstrap contained age (40.5%), gender (24.5%), education (5.2%), income satisfaction (10.6%), tool satisfaction (8.4%) and smoking (10.8%). Problem attentions to MSDs are identical in developed and newly industrialized countries. However, factors are not exact similar. Interventions targeted at manual activities for degrading risk factors that furnish to MSDs are necessary.
Keywords: Agricultural systems; Information theory; Musculoskeletal disorders; Manual working; Marginal farmers; R statistical software.
Two-sided assembly line car sequencing with a fuzzy adaptive extended coincidence algorithm
by Parames Chutima, Watcharawit Tanontong
Abstract: The car sequencing problem is a constraint satisfaction problem that has attracted the attention of academia and practitioners for many years now. In this paper, the industrial version of the car sequencing problem is extended to reflect more real operations in practice by using a two-sided assembly line instead of classical single-sided one. The fuzzy adaptive extended coincidence algorithm (COIN-F) is developed to optimise the multi-objective car sequencing problem in a Pareto sense. The relative performance of COIN-F is compared against COIN-E, NSGA-II and DPSO. Experimental results demonstrate the effectiveness of COIN-F over the contestant algorithms, especially in the search for the approximate true-Pareto frontier.
Keywords: Car sequencing; two-sided assembly line; COIN; fuzzy adaptive.
A novel kind of electro-hydraulic loading system based on friction for actuator test
by Chenghu Jing, Hongguang Xu
Abstract: Conventional electric or electrohydraulic load simulator is disturbed by the motion of the tested system. To eliminate the strong motion disturbance and improve loading performance, a novel kind of friction electrohydraulic loading system is proposed. The mechanism of friction electrohydraulic loading system is described in detail. The math model for the loading torque and the input signal has been deduced, which indicates that this proposed friction electrohydraulic loading system has no disturbances resulting from tested actuators under ideal conditions. However, friction coefficient is time-varying and uncertain. The friction device increases the load inertia of the actuator. The additional inertia may affect the loading performance. The structure mechanism has been optimized to reduce the rotary inertia. To verify the loading performance of friction electrohydraulic loading system, simulations and experiments are carried out. Compared with conventional electrohydraulic load simulator, the theoretical analysis and experimental results validate the feasibility of the friction electrohydraulic loading method. The novel friction electrohydraulic load simulator, with a simple control principle and easy engineering constructability, can provide accurate torque simulation for actuator test.
Keywords: Electrohydraulic system; load simulator; loading system; motion disturbance; extraneous torque; actuator test.
Integrated supplier-buyer cooperative models with price-dependent demand and process quality improvement under two-part trade credit policy
by Hsien-Jen Lin
Abstract: This paper deals with an integrated supplier-buyer inventory model with process quality improvement where market demand is sensitive to the retail price and the supplier adopts two-part trade credit policy. The model has some insights in order to obtain optimal strategy of a business firm. The objectives of this paper are twofold. Firstly, we want to correct and improve the recently studied model by simultaneously optimizing order quantity, defective rate, retail price, and number of shipments from the supplier to the buyer to maximize the joint total profit. Secondly, we consider that the demand rate is retail price dependent and the production rate is finite and proportional to the demand rate to fit the real-life situations. For the proposed model, a computational algorithm is proposed for determining the optimal solution. Furthermore, numerical examples are provided to illustrate the modeling idea and effectiveness of the algorithm. Sensitivity analysis is conducted and some managerial implications are presented.
Keywords: integrated inventory model; two-part trade credit; price elasticity; quality improvement; capital investment.
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 aluminum electrolytic capacitor
by Zheng Tian-Chi, Qui Zi-Xue, Shao Jian-Luin, Lu Guan, Jiang Yuan
Abstract: Aiming at the problems existing in the glue-pouring process of capacitor aluminum 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 aluminum shell is proposed. And, the quantitative glue-pouring system of aluminum 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 aluminum 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 aluminum shell, and the system has good practical application value.
Keywords: aluminum electrolytic capacitor; aluminum 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.