eng
International Journal of Supply and Operations Management
2014-05-01
1
1
1
19
1900
مقاله پژوهشی
Analysis of an M/G/1 Queue with Multiple Vacations, N-policy, Unreliable Service Station and Repair Facility Failures
Wenqing Wu
wwqing0704@swust.edu.cn
1
Yinghui Tang
2
Miaomiao Yu
3
School of Mathematics & Software Science, Sichuan Normal University, Chengdu, Sichuan, 610068, China
School of Mathematics & Software Science, Sichuan Normal University, Chengdu, Sichuan, 610068, China
School of Science, Sichuan University of Science and Engineering, Zigong, Sichuan, 643000, China
This paper studies an M/G/1 repairable queueing system with multiple vacations and N-policy, in which the service station is subject to occasional random breakdowns. When the service station breaks down, it is repaired by a repair facility. Moreover, the repair facility may fail during the repair period of the service station. The failed repair facility resumes repair after completion of its replacement. Under these assumptions, applying a simple method, the probability that the service station is broken, the rate of occurrence of breakdowns of the service station, the probability that the repair facility is being replaced and the rate of occurrence of failures of the repair facility along with other performance measures are obtained. Following the construction of the long-run expected cost function per unit time, the direct search method is implemented for determining the optimum threshold N* that minimises the cost function.
http://www.ijsom.com/pdf_1900_4881c207b3f40995f3c0c24db851ca30.html
M/G/1 repairable queue
Multiple vacations
Min (N, V)-policy
Reliability measure
Cost function
eng
International Journal of Supply and Operations Management
2014-05-01
1
1
20
37
1901
مقاله پژوهشی
EOQ Model for Deteriorating Items with Exponential Time Dependent Demand Rate under Inflation When Supplier Credit Linked to Order Quantity
Rakesh Prakash Tripathi
tripathi_rp0231@rediffmail.com
1
Dinesh Singh
2
Tushita Mishra
3
Department of Mathematics, Graphic Era University, Dehradun (UK) India
Department of Mathematics, S.G.R.R. PG College, Dehradun (UK) India
Department of Mathematics, S.G.R.R. PG College, Dehradun (UK) India
In paper (2004) Chang studied an inventory model under a situation in which the supplier provides the purchaser with a permissible delay of payments if the purchaser orders a large quantity. Tripathi (2011) also studied an inventory model with time dependent demand rate under which the supplier provides the purchaser with a permissible delay in payments. This paper is motivated by Chang (2004) and Tripathi (2011) paper extending their model for exponential time dependent demand rate. This study develops an inventory model under which the vendor provides the purchaser with a credit period; if the purchaser orders large quantity. In this chapter, demand rate is taken as exponential time dependent. Shortages are not allowed and effect of the inflation rate has been discussed. We establish an inventory model for deteriorating items if the order quantity is greater than or equal to a predetermined quantity. We then obtain optimal solution for finding optimal order quantity, optimal cycle time and optimal total relevant cost. Numerical examples are given for all different cases. Sensitivity of the variation of different parameters on the optimal solution is also discussed. Mathematica 7 software is used for finding numerical examples.
http://www.ijsom.com/pdf_1901_1a5d3d8e8f818b5f034fcb884c8d82b8.html
Inventory
Inflation
Exponential time dependent
Credit
Finance
eng
International Journal of Supply and Operations Management
2014-05-01
1
1
38
53
1902
مقاله پژوهشی
Location-Routing Problem with Fuzzy Time Windows and Traffic Time
Shima Teimoori
1
Hasan Khademi Zare
hkhademiz@yazd.ac.ir
2
Mohammad Saber Fallah Nezhad
fallahnezhad@yazd.ac.ir
3
Department of Industrial Engineering, Elmo Honar University
Department of Industrial Engineering, Yazd University
Department of Industrial Engineering, Yazd University
The location-routing problem is a relatively new branch of logistics system. Its objective is to determine a suitable location for constructing distribution warehouses and proper transportation routing from warehouse to the customer. In this study, the location-routing problem is investigated with considering fuzzy servicing time window for each customer. Another important issue in this regard is the existence of congested times during the service time and distributing goods to the customer. This caused a delay in providing service for customer and imposed additional costs to distribution system. Thus we have provided a mathematical model for designing optimal distributing system. Since the vehicle location-routing problem is Np-hard, thus a solution method using genetic meta-heuristic algorithm was developed and the optimal sequence of servicing for the vehicle and optimal location for the warehouses were determined through an example.
http://www.ijsom.com/pdf_1902_14027a3b0ff536b5ab658cbf0d9a2f0d.html
Locating Routing
Fuzzy time window
Satisfaction level
Congested times
eng
International Journal of Supply and Operations Management
2014-05-01
1
1
54
68
1903
مقاله پژوهشی
No-idle time Scheduling of Open shops: Modeling and Meta-heuristic Solution Methods
Bahman Naderi
bahman_naderi62@yahoo.com
1
Vahid Roshanaei
vroshana@mie.utoronto.ca
2
Department of Industrial Engineering, Faculty of Engineering, University of Kharazmi, Tehran, Iran
Department of Industrial Engineering, University of Toronto, Toronto, Canada
In some industries as foundries, it is not technically feasible to interrupt a processor between jobs. This restriction gives rise to a scheduling problem called no-idle scheduling. This paper deals with scheduling of no-idle open shops to minimize maximum completion time of jobs, called makespan. The problem is first mathematically formulated by three different mixed integer linear programming models. Since open shop scheduling problems are NP-hard, only small instances can be solved to optimality using these models. Thus, to solve large instances, two meta-heuristics based on simulated annealing and genetic algorithms are developed. A complete numerical experiment is conducted and the developed models and algorithms are compared. The results show that genetic algorithm outperforms simulated annealing.
http://www.ijsom.com/pdf_1903_0d44b3dce86860e16d114195990edcfb.html
Scheduling
Open shop
No idle time
Mixed integer linear programming
Simulated Annealing
Genetic Algorithm
eng
International Journal of Supply and Operations Management
2014-05-01
1
1
69
80
1904
مقاله پژوهشی
Alternative Axiomatic Characterizations of the Grey Shapley Value
Sirma Zeynep Alparslan Gok
1
Osman Palanci
osmanpalanci@sdu.edu.tr
2
Mehmet Onur Olgun
3
Süleyman Demirel University, Faculty of Arts and Sciences, Department of Mathematics, 32260 Isparta, Turkey
Süleyman Demirel University, Faculty of Arts and Sciences, Department of Mathematics, 32260 Isparta, Turkey
Süleyman Demirel University, Faculty of Arts and Sciences, Department of Mathematics, 32260 Isparta, Turkey
The Shapley value, one of the most common solution concepts of cooperative game theory is defined and axiomatically characterized in different game-theoretic models. Certainly, the Shapley value can be used in interesting sharing cost/reward problems in the Operations Research area such as connection, routing, scheduling, production and inventory situations. In this paper, we focus on the Shapley value for cooperative games, where the set of players is finite and the coalition values are interval grey numbers. The central question in this paper is how to characterize the grey Shapley value. In this context, we present two alternative axiomatic characterizations. First, we characterize the grey Shapley value using the properties of efficiency, symmetry and strong monotonicity. Second, we characterize the grey Shapley value by using the grey dividends.
http://www.ijsom.com/pdf_1904_c4411fe5a33e6024c0a9d9590b73a00e.html
Cooperative games
Uncertainty
Grey numbers
The Shapley value
Dividends
Decision making
Operations Research
eng
International Journal of Supply and Operations Management
2014-05-01
1
1
81
107
1905
مقاله پژوهشی
Analyzing Bullwhip Effect in Supply Networks under Exogenous Uncertainty
Mitra Darvish
m_darvish1986@yahoo.com
1
Mehdi Seifabrghy
2
Mohammad Ali Saniei Monfared
mas_monfared@yahoo.com
3
Fatemeh Akbari
4
Industrial Engineering Department, Alzahra University, Tehran, Iran.
Industrial Engineering Department, Alzahra University, Tehran, Iran
Industrial Engineering Department, Alzahra University, Tehran, Iran
Industrial Engineering Department, Alzahra University, Tehran, Iran
This paper explains a model for analyzing and measuring the propagation of order amplifications (i.e. bullwhip effect) for a single-product supply network topology considering exogenous uncertainty and linear and time-invariant inventory management policies for network entities. The stream of orders placed by each entity of the network is characterized assuming customer demand is ergodic. In fact, we propose an exact formula in order to measure the bullwhip effect in the addressed supply network topology considering the system in Markovian chain framework and presenting a matrix of network member relationships and relevant order sequences. The formula turns out using a mathematical method called frequency domain analysis. The major contribution of this paper is analyzing the bullwhip effect considering exogenous uncertainty in supply networks and using the Fourier transform in order to simplify the relevant calculations. We present a number of numerical examples to assess the analytical results accuracy in quantifying the bullwhip effect.
http://www.ijsom.com/pdf_1905_210f65d79e1a376b50f242f5dc2bab75.html
Supply Chain Management
Inventory
Bullwhip effect
Exogenous uncertainty
Frequency domain analysis
eng
International Journal of Supply and Operations Management
2014-05-01
1
1
108
128
1906
Managing Virtual Product Development team: A Review
Amir Mohammad Colabi
1
Behrouz Zarei
bzarei@ut.ac.ir
2
Faculty of Entrepreneurship, University of Tehran, Tehran, Iran
Faculty of Entrepreneurship, University of Tehran, Tehran, Iran
Although there are many potential benefits associated with the use of virtual product development teams, exploiting these benefits requires an appropriate management. Managing virtual product development team is a critical issue as many of these teams fail to accomplish their goals. Review of previous literature shows that body of knowledge in managing virtual product development teams is fragmented and inconsistent. The main objective of this paper is to categorize the previous research on the subject of virtual product development team management in order to integrate the research into a thematic model and to enable recommendations for future research. So, this study reviews and summarizes empirical research in the field, also conceptual and qualitative papers, experiences, reports and explorative case studies. Results show that there are three fields of research in this area, including: Virtual production and Virtual team in Product Development, Managing virtual team in R&D[1] and product development, Managing global virtual product development teams. In order to organize previous studies in this area, a thematic map is proposed which shows the structure and sequence of research. Finally, a comprehensive discussion on the future directions in this field is proposed. [1] Research & Development
http://www.ijsom.com/pdf_1906_ff3bbb743dc4e0546abf744ffbebc3fb.html
Virtual teams
Product development
Virtual production
Global managing