Optimal pricing and inventory policies for non-instantaneous deteriorating items with permissible delay in payment: Fuzzy expected value model
, Pages 281-300
Hardik N Soni and Kamlesh A Patel PDF (396 K)
Abstract: This study investigates optimal pricing and inventory policies for non-instantaneous deteriorating items with permissible delay in payment. The demand rate is as known, continuous and differentiable function of price while holding cost rate, interest paid rate and interest earned rate are characterized as independent fuzzy variables rather than fuzzy numbers as in previous studies. Under these general assumptions, we first formulated a fuzzy expected value model (EVM) and then some useful theoretical results have been derived to characterize the optimal solutions. An efficient algorithm is designed to determine the optimal pricing and inventory policy for the proposed model. The algorithmic procedure is demonstrated by means of numerical examples.
Keywords: Fuzzy expected value inventory model, Non-instantaneous deterioration, Pricing, Partial backlogging
Permutation based decision making under fuzzy environment using Tabu search
, Pages 301-312
Mahdi Bashiri Mehdi Koosha and Hossein Karimi PDF (252 K)
Abstract: One of the techniques, which are used for Multiple Criteria Decision Making (MCDM) is the permutation. In the classical form of permutation, it is assumed that weights and decision matrix components are crisp. However, when group decision making is under consideration and decision makers could not agree on a crisp value for weights and decision matrix components, fuzzy numbers should be used. In this article, the fuzzy permutation technique for MCDM problems has been explained. The main deficiency of permutation is its big computational time, so a Tabu Search (TS) based algorithm has been proposed to reduce the computational time. A numerical example has illustrated the proposed approach clearly. Then, some benchmark instances extracted from literature are solved by proposed TS. The analyses of the results show the proper performance of the proposed method.
Keywords: Tabu search, Fuzzy decision making, Permutation based decision making, NP-Hard
Planning Annuaulised hours when spike in demand exists
, Pages 313-320
MR Sureshkumar and V Madhusudanan Pillai PDF (156 K)
Abstract: Manpower planning using annualised hours is an effective tool where seasonal demand for staff in industry exists. In annualised hours (AH) workers are contracted to work for a certain number of hours per year. The workers are associated with relative efficiency for different types of tasks. This paper proposes a Mixed Integer linear Programming (MILP) model to solve an annualised working hours planning problem when spike in demand exists. The holiday weeks for the workers are considered as partially individualised. If a worker has been assigned with more than one type of working week in a week, this will be compensated with one or more holiday week. The performance of the model is demonstrated with an example. It can be seen that this type of modelling helps to meet the spikes in demand with less capacity shortage compared with one working week in a week.
Keywords: Manpower planning, Annualised hours, Mixed integer linear programming Holiday weeks, Flexible working
Just-in-time preemptive single machine problem with costs of earliness/tardiness, interruption and work-in-process
, Pages 321-336
Mohammad Kazemi, Elnaz Nikoofarid, Amin Aalaei and Reza Kia PDF (276 K)
Abstract: This paper considers preemption and idle time are allowed in a single machine scheduling problem with just-in-time (JIT) approach. It incorporates Earliness/Tardiness (E/T) penalties, interruption penalties and holding cost of jobs which are waiting to be processed as work-in-process (WIP). Generally in non-preemptive problems, E/T penalties are a function of the completion time of the jobs. Then, we introduce a non-linear preemptive scheduling model where the earliness penalty depends on the starting time of a job. The model is liberalized by an elaborately–designed procedure to reach the optimum solution. To validate and verify the performance of proposed model, computational results are presented by solving a number of numerical examples.
Keywords: Just-in-time, Preemption, Earliness/Tardiness, Interruption Penalties, Work-In-Process, Single Machine Scheduling
Performance analysis of supply chains under customer demand information sharing using role play game
, Pages 337-346
T. Chinna Pamulety and V. Madhusudanan Pillai PDF (890 K)
Abstract: Supply chain is a network of organizations that work together and performs various business functions such as procurement of raw materials, converting the raw material into semi-finished or finished goods and distributing the same to their ultimate customers. Presence of bullwhip effect in a supply chain is costly and degrades the performance of the supply chain. Reduction in bullwhip effect can improve the efficiency or profitability of a supply chain. The objective of this paper is to know the impact of imperfect Advance Demand Information (ADI) sharing on bullwhip effect in a four-stage serial supply chain and to evaluate the supply chain performance by conducting an experiment similar to the beer distribution game. The performance measures used are variance of orders placed by each stage, fill rate, total inventory at each stage and total holding cost of the supply chain. Results show that imperfect ADI improves the performance of the supply chain. The performance of the supply chain is also evaluated under order up to level (R, S) policy with safety stock and it is found that the performance of supply chain is better when inventory policy used.
Keywords: Supply Chain, Bullwhip Effect, Imperfect ADI, (R, S) Policy
Single-machine batch scheduling minimizing weighted flow times and delivery costs with job release times
, Pages 347-364
Mohammad Mahdavi Mazdeh, Ali Naji Esfahani, Seyyed Ershad Sakkaki and Amir Ebrahimzadeh Pilerood PDF (360 K)
Abstract: This paper addresses scheduling a set of weighted jobs on a single machine in presence of release date for delivery in batches to customers or to other machines for further processing. The problem is a natural extension of minimizing the sum of weighted flow times by considering the possibility of delivering jobs in batches and introducing batch delivery costs. The classical problem is NP-hard and then the extended version of the problem is NP-hard. The objective function is that of minimizing the sum of weighted flow times and delivery costs. The extended problem arises in a real supply chain network by cooperation between two layers of chain. Structural properties of the problem are investigated and used to devise a branch-and-bound solution scheme. Computational experiments show the efficiency of suggested algorithm for solving instances up to 40 jobs.
Keywords: Scheduling, Single machine, Batch delivery, Branch and bound, Weighted flowtimes
Weighted Euclidean distance based approach as a multiple attribute decision making method for plant or facility layout design selection
, Pages 365-382
R. Venkata Rao and Dinesh Singh PDF (346 K)
Abstract: In response to increasing inflexible customer demands and to improve the competitive advantage, industrial organizations have to adopt strategies to achieve cost reduction, continual quality improvement, increased customer service and on-time delivery performance. Selection of the most suitable plant or facility layout design for an organization is one among the most important strategic issues to fulfill all these above-mentioned objectives. Nowadays, many industrial organizations have come to realize the importance of proper selection of the plant or facility layout design to survive in the global competitive market. Selecting the proper layout design from a given set of candidate alternatives is a difficult task, as many potential qualitative and quantitative criteria need to be considered. This paper proposes a Euclidean distance based approach (WEDBA) as a multiple attribute decision making method to deal with the complex plant or facility layout design problems of the industrial environment. Three examples are included to illustrate the approach.
Keywords: Plant layout design, Multiple attribute decision making, Weighted Euclidean distance based approach
Supply chain coordination under retail competition and advertising dependent demand
, Pages 383-392
Mehdi Mirzaee, Ahmad Makui and Ebrahim Manzari Tavakoli PDF (233 K)
Abstract: Supply chain coordination as an effective tool plays an important role in improving supply chain performance. In this article, a two-level supply chain with one manufacturer and two retailers is considered. The order quantity that retailers are faced with depends on the amount of advertisements and both retailers compete with each other on advertising. The Stackelberg game is established between manufacturer and retailers such that the manufacturer and the retailers play the leader and the follower roles, respectively. First, the manufacturer determines the wholesale prices for retailers and instead, the retailers determine the order quantity and advertising level, simultaneously. The manufacturer produces one kind of product and delivers it to retailers before the beginning of selling season. Retailers can affect the order quantity regarding the demand dependency on advertising level through the incurred costs from the advertising. In this paper, we show that we can achieve the desirable supply chain coordination through using combined quantity discount and advertising cost sharing contracts. We also consider the win-win situation for all the members of the supply chain.
Keywords: Supply chain coordination, Advertising cost sharing contract, Quantity discount contract Retail competition
Supplier evaluation in manufacturing environment using compromise ranking method with grey interval numbers
, Pages 393-402
Prasenjit Chatterjee, and Rupsa Chatterjee PDF (263 K)
Abstract: Evaluation of proper supplier for manufacturing organizations is one of the most challenging problems in real time manufacturing environment due to a wide variety of customer demands. It has become more and more complicated to meet the challenges of international competitiveness and as the decision makers need to assess a wide range of alternative suppliers based on a set of conflicting criteria. Thus, the main objective of supplier selection is to select highly potential supplier through which all the set goals regarding the purchasing and manufacturing activity can be achieved. Because of these reasons, supplier selection has got considerable attention by the academicians and researchers. This paper presents a combined multi-criteria decision making methodology for supplier evaluation for given industrial applications. The proposed methodology is based on a compromise ranking method combined with Grey Interval Numbers considering different cardinal and ordinal criteria and their relative importance. A ‘supplier selection index’ is also proposed to help evaluation and ranking the alternative suppliers. Two examples are illustrated to demonstrate the potentiality and applicability of the proposed method.
Keywords: Supplier selection, Multi-criteria decision making Compromise ranking method, Grey interval number, Grey Supplier selection index
A fuzzy mixed integer linear programming model for integrating procurement-production-distribution planning in supply chain
, Pages 403-412
Alireza Pourrousta, Saleh Dehbari, Reza Tavakkoli-Moghaddam, Amir Imenpour and Mahdi Naderi-Beni PDF (313 K)
Abstract: In this paper, we study a supply chain problem where a whole seller/producer distributes goods among different retailers. Such problems are always faces with uncertainty with input data and we have to use various techniques to handle the uncertainty. The proposed model of this paper considers different input parameters such as demand, capacity and cost in trapezoid fuzzy forms and using two ranking methods, we handle the uncertainty. The results of the proposed model of this paper have been compared with the crisp and other existing fuzzy techniques using some randomly generated data. The preliminary results indicate that the proposed models of this paper provides better values for the objective function and do not increase the complexity of the resulted problem.
Keywords: Jimenez fuzzy technique, Cadenas & Verdegay fuzzy technique, VRP, Time window
Make or buy strategy decision making in supply quality chain
, Pages 413-422
Seyed Mohammad Seyedhosseini, Faezeh Mohammadipour, and Milad Gorji Ashtiani PDF (255 K)
Abstract: Minimizing the total cost is absolutely the goal of each supply chain, which is most of the time pursued. In this regards, quality related costs that have significant roles are sometimes neglected. Selecting suppliers, which supply relatively high quality raw materials in a lower cost is considered as a strategic decision. Make or Buy decision can be also noticed in supplier selection process. In this paper, the supply strategy: Make or Buy decision (SS: MOB) is studied in order to find which strategy (Make or Buy) should be chosen to minimize the total costs of supply chain. Therefore, two separate models are generated for each strategy and several examples are solved for the respective models. Computational experiments show the efficiency of the proposed models for making decision about selecting the best strategy.
Keywords: Cost minimization, Supplier selection, Make or Buy decision, Outsourcing, Insourcing
RAM investigation of coal-fired thermal power plants: A case study
, Pages 423-434
D. D. Adhikary, G. K. Bose, S Chattopadhyay, D. Bose and S. Mitra PDF (231 K)
Abstract: Continuous generation of electricity of a power plant depends on the higher availability of its components/equipments. Higher availability of the components/equipments is inherently associated with their higher reliability and maintainability. This paper investigates the reliability, availability and maintainability (RAM) characteristics of a 210 MW coal-fired thermal power plant (Unit-2) from a thermal power station in eastern region of India. Critical mechanical subsystems with respect to failure frequency, reliability and maintainability are identified for taking necessary measures for enhancing availability of the power plant and the results are compared with Unit-1 of the same Power Station. Reliability-based preventive maintenance intervals (PMIs) at various reliability levels of the subsystems are estimated also for performing their preventive maintenance (PM). The present paper highlights that in the Unit-2, Economizer (ECO) & Furnace Wall Tube (FWT) exhibits lower reliability as compared to the other subsystems and Economizer (ECO) & Baffle Wall Tube (BWT) demands more improvement in maintainability. Further, it has been observed that FSH followed Decreasing Failure Rate (DFR) and Economizer (ECO) is the most critical subsystem for both the plants. RAM analysis is very much effective in finding critical subsystems and deciding their preventive maintenance program for improving availability of the power plant as well as the power supply.
Keywords: RAM investigation, Coal-fired Thermal, Power Plant Critical Subsystem Preventive Maintenance, Interval Decreasing Failure Rate, Increasing Failure Rate
Rapid Ant based clustering-genetic algorithm (RAC-GA) with local search for clustering problem
, Pages 435-444
Yaghub pirzadeh, Jamal shahrabi, and Mohamad taghi taghavifard PDF (286 K)
Abstract: Clustering is a critical data analysis and it is a popular data mining technique. This paper presents a rapid Ant based clustering-genetic algorithm (RAC-GA) with local search to solve clustering problem. GA and local search are used as a global and local search to obtain better results. The proposed algorithm is evaluated by testing on some of the well-known real-world datasets, and the results are compared with other popular heuristics in clustering, such as GA, SA, TS, ACO and RAC. The results show strong improvement both in quality solution and process time area, especially in process time which is much less than previous algorithms
Keywords: Genetic algorithm, Clustering problem, RAC-GA, Local search
An EPQ model under two levels of trade credit and limited storage space
, Pages 445-462
Alok kumar, K K Kaanodiya and R R Pachauri PDF (257 K)
Abstract: In this article, a production inventory model is developed to determine the retailer’s optimal replenishment decisions under two levels of trade credit and limited storage space. Two levels of trade credit refers that the supplier provides to his/her retailer a permissible delay period to settle the account and the retailer also in turn provides a delay period to his/her customer for paying of purchasing goods. The retailer’s credit period M offered by supplier is greater than customers credit period N provides by the retailer. This paper investigates retailer optimal replenishment policy under finite replenishment rate by minimizing the total annual inventory cost. Three theorems are developed to determine optimal cycle time, optimal relevant cost and optimal order quantity for retailers accurate and rapidly. A numerical example is used to analyze the validity of propose model, Sensitive analysis shows managerial decisions for retailer.
Keywords: EPQ, Trade credit, Limited storage space, Inventory
Evaluating high risks in large-scale projects using an extended VIKOR method under a fuzzy environment
, Pages 463-476
S. Ebrahimnejad, S. M. Mousavi, R Tavakkoli-Moghaddam and M Heydar PDF (130 K)
Abstract: The complexity of large-scale projects has led to numerous risks in their life cycle. This paper presents a new risk evaluation approach in order to rank the high risks in large-scale projects and improve the performance of these projects. It is based on the fuzzy set theory that is an effective tool to handle uncertainty. It is also based on an extended VIKOR method that is one of the well-known multiple criteria decision-making (MCDM) methods. The proposed decision-making approach integrates knowledge and experience acquired from professional experts, since they perform the risk identification and also the subjective judgments of the performance rating for high risks in terms of conflicting criteria, including probability, impact, quickness of reaction toward risk, event measure quantity and event capability criteria. The most notable difference of the proposed VIKOR method with its traditional version is just the use of fuzzy decision-matrix data to calculate the ranking index without the need to ask the experts. Finally, the proposed approach is illustrated with a real-case study in an Iranian power plant project, and the associated results are compared with two well-known decision-making methods under a fuzzy environment.
Keywords: Risk evaluation, Large-scale projects, Fuzzy sets, VIKOR
A fuzzy neural network to estimate at completion costs of construction projects
, Pages 477-484
Mohammad Reza Feylizadeh, Ayad Hendalianpour and Morteza Bagherpour PDF (209 K)
Abstract: In construction cost management system, normally earned value management (EVM) is applied as an efficient control approach in both status detection and estimation at completion (EAC) cost forecasting. The traditional approaches in EAC predictions normally extend the current situation of a project to the future by employing pervious performance factor. The proposed approach of this paper considers both qualitative and quantitative factors affecting the EAC prediction. The proposed approach of this research not only estimates the completion of the project, but also it can generate accurate forecast for the entire future periods using a fuzzy neural network model. The model is also implemented for a real-world case study and yields encouraging preliminary results.
Keywords: EAC, Earned value management, Fuzzy neural network, Construction cost management
Risk mitigation in the implementation of AMTs: A guiding framework for future
, Pages 485-498
Bhaskar Nagar and Tilak Raj PDF (198 K)
Abstract: The fast industrial development increases different types of risks for the industries. Many risk factors are inherent in the implementation of advanced manufacturing technologies (AMTs). Industries are developing methodologies for risk prevention and protection. The present research focuses to identify various risks that could influence the implementation of AMTs, and develop a framework to mitigate them. For this framework, interpretive structural modeling(ISM) has been used to depict the relationship and priority among the various risks. This research provides a path for managers and indicates the dominant risks on the basis of higher driving power. Also, this research classifies the relationship among various risks in AMTs implementation according to their driving power and dependence. The risks have been categorized into four categories as autonomous risks, linkage risks, dependent risks and independent risks. The proposed hierarchal model would help the management to effectively handle and develop strategies against the risks and hence new and latest technologies can be adopted with ease and effectiveness.
Keywords: AMTs, ISM, Implementation
A branch and bound for single machine stochastic scheduling to minimize the maximum lateness
, Pages 499-510
Hamidreza Haddad, Mohammad Ebrahim Arbabian and Keyvan Kamandani Pour PDF (254 K)
Abstract: This paper studies the problem of single machine stochastic scheduling with random processing times, deterministic due dates and an independent setup time. The jobs are also deteriorated based on the position, which their processes are done. The objective function is to find a schedule of jobs, which minimizes the expected value of maximum lateness. A branch and bound scheme is presented to solve the problem analytically and a simulated annealing meta-heuristic (SA) is also provided for solving the problem in larger scales. Computational experiments demonstrate that the proposed SA is capable of finding near optimal solutions with very low gap.
Keywords: Stochastic scheduling, Single machine, Tardy jobs, Deterioration
Tool flank wear model and parametric optimization in end milling of metal matrix composite using carbide tool: Response surface methodology approach
, Pages 511-518
R. Arokiadass, K. Palaniradja and N.Alagumoorthi PDF (506 K)
Abstract: Highly automated CNC end milling machines in manufacturing industry requires reliable model for prediction of tool flank wear. This model later can be used to predict the tool flank wear (VBmax) according to the process parameters. In this investigation an attempt was made to develop an empirical relationship to predict the tool flank wear (VBmax) of carbide tools while machining LM25 Al/SiCp incorporating the process parameters such as spindle speed (N), feed rate (f), depth of cut (d) and various % wt. of silicon carbide (S). Response surface methodology (RSM) was applied to optimizing the end milling process parameters to attain the minimum tool flank wear. Predicted values obtained from the developed model and experimental results are compared, and error <5 percent is observed. In addition, it is concluded that the flank wear increases with the increase of SiCp percentage weight in the MMC.
Keywords: End Milling, Metal Matrix Composite, Response surface methodology, Tool flank wear, Optimization, Contour plots
A note on “An alternative multiple attribute decision making methodology for solving optimal facility layout design selection problems”
, Pages 519-524
R. Venkata Rao PDF (156 K)
Abstract: A paper published by Maniya and Bhatt (2011) (An alternative multiple attribute decision making methodology for solving optimal facility layout design selection problems, Computers & Industrial Engineering, 61, 542-549) proposed an alternative multiple attribute decision making method named as “Preference Selection Index (PSI) method” for selection of an optimal facility layout design. The authors had claimed that the method was logical and more appropriate and the method gives directly the optimal solution without assigning the relative importance between the facility layout design selection attributes. This note discusses the mathematical validity and the shortcomings of the PSI method.
Keywords: Facility layout design, Multiple attribute decision making, Preference selection index
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