2018-09-24T15:03:08Z
http://scientiairanica.sharif.edu/?_action=export&rf=summon&issue=338
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
A novel project portfolio selection framework: An application of fuzzy DEMATEL and multi-choice goal programming
B.H.
Tabrizi
S.A.
Torabi
S.F.
Ghaderi
Project portfolio selection is an important problem for having an ecient and eective project management. This paper proposes a new framework to identify the optimal project portfolio. First, the in uencing criteria are derived with respect to higher priorities from the fuzzy DEMATEL method under the balanced scorecard framework. Afterwards, a utility-based multi-choice goal programming technique is applied to determine the project portfolio in regard to the chosen criteria and some other operational limitations. The synergy amongst projects and the outsourcing option are also taken into account in order to provide a more realistic selection process. Finally, applicability and validity of the proposed integrated model are tested by a case study conducted in a pharmaceutical company.
Project portfolio selection
Projects synergy
Fuzzy DEMATEL
Multi-Choice Goal Programming
2016
12
01
2945
2958
http://scientiairanica.sharif.edu/article_4004_308de94bd9d4e2d543616b809223ae45.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
Application of fuzzy group analytic hierarchy process in partner selection of international joint venture projects
S.
Kimiagari
S.
Keivanpour
F.
Jolai
M.
Moazami
Partner selection is gradually recognized as an essential factor in gaining success in a cooperative settings. In this paper, a novel approach based on fuzzy AHP group decision-making for partner selection of joint venture projects is proposed. In this approach, rst, the in uential factors for selection of appropriate partners based on literature review and interviews with experts are identied. Then, using a method considering the risk, knowledge, and educational background of decision-makers, the impact of decision-makers is calculated. Pairwise comparison matrices are performed, and the weights of criteria are calculated based on two methods (multiplicative and additive). Then, the calculated weights of criteria and the potential partners have been ranked via an ecient ranking index. Finally, the application of this methodology to a real case study in National Iranian Petrochemical Company (NPC) is conducted. The contribution of this study is developing a fresh systematic approach for partner selection of international joint ventures and application in a real-life case study to present an operational guideline to the petrochemical industries. The results of this study reveal that the equipment of the partner, its nancial capacity, trusts and management skills are the most important criteria for establishing the durable partners in the international joint venture of NPC.
International joint ventures
Partner selection
Fuzzy group AHP
MCDM
Petrochemical company
2016
12
01
2959
2976
http://scientiairanica.sharif.edu/article_4005_88d646059d38ccbfe52897b2dce77d40.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
Multi-objective Sustainable Supply Chain with Deteriorating Products and Transportation Options under Uncertain Demand and Backorder
Mehran
Sepehri
Zeinab
Sazvar
Supply chain sustainability, with economic, environment and social values, has gained attention in both academia and industry. For deteriorating and seasonal products, like fresh produce, the issue of timely supply and disposal of the deteriorated products are of great concern. This paper is to develop a possibilistic mathematical model, solved after linearizing the non-linear statements, and to propose a new replenishment policy for a centralized sustainable supply chain (SSC) for deteriorating items. Different transportation vehicle options produce various pollution and greenhouse gas (GHG) levels are considered. Several variables are uncertain as the end-customer demand, the partial backordered ratio and the deterioration rate. Deterioration occurs for in-stock inventories and during transportation. The solution provides the optimum transportation modes and routes and the inventory policy by finding a balance between financial, environmental and social criteria.
Sustainable Supply Chain
Deteriorating Products
Transportation
Possibilistic Programming
Green
2016
12
01
2977
2994
http://scientiairanica.sharif.edu/article_4006_94c4acc7b02301d97d7743bc97883fd4.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
Step Change Point Estimation of the First-order Autoregressive Autocorrelated Simple Linear Profiles
Reza
Baradaran Kazemzadeh
Amirhossein
Amiri
Hamidreza
Mirbeik
In most researches in the area of profile monitoring, it is assumed that observations are independent of each other. Whereas, this assumption is usually violated in practice and observations are autocorrelated. The control charts are the most important tools of the statistical process control which are used to monitor the processes over time. The control charts usually signal the out-of-control status of the process with a time delay. Whereas knowing real-time of the change (change point), one can achieve great savings on time and expenses. In this paper, the estimation of the change point in the simple linear profiles with AR (1) autocorrelation structure within each profile is considered. In the proposed method, by acquiring the joint probability density function of the autocorrelated observations, the maximum likelihood estimation method is applied to estimate the step change point. Here, we specifically focus on Phase II and compare the performance of the proposed estimator with the existing estimators in the literature through simulation studies. In addition, the application of the proposed estimator in comparison with the two estimators is illustrated through a real case. The results show the better performance of the proposed estimator.
Simple linear profile
Autocorrelation
step change point
AR (1)
Phase II
2016
12
01
2995
3008
http://scientiairanica.sharif.edu/article_4007_e32ae6ef31075bab7a7d0740e0864d07.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
An integrated model for supplier location-selection & order allocation under capacity constraints in an uncertain environment
Fatemeh
Ranjbar Tezenji
Mohammad
Mohammadi
Seyed Hamid Reza
Pasandideh
Mehrdad
Nouri Koupaei
Facility/supplier location-allocation and supplier selection-order allocation are two of the most important decisions for both designing and operation supply chains. Conventionally these two issues will be discussed separately. Due to similarity and relationship between these issues, in this paper we investigate an integrated model for supplier location-selection and order allocation problem in supply chain management (SCM). The objective function is set in such a way that the establishment costs, inventory-related costs, and transportation costs as quantitative criteria have been minimized. As regards, the costs are uncertainty, therefore we have considered them stochastic. This paper developed a bi-objective model for optimization of the mean and variance of costs. Also, the capacities of supplier are limited. This mixed integer nonlinear program solved with two meta-heuristics methods: genetic algorithm and simulated annealing. Finally, these two methods compared in terms of both solution quality and computational time. To obtain a high degree of validity and reliability GAMS software and meta-heuristic results in small sizes compared.
Location-allocation
Supplier selection
Inventory management
Multi-objective problem
Meta-Heuristic
Multiple Attribute Decision Making (MADM)
2016
12
01
3009
3025
http://scientiairanica.sharif.edu/article_4008_9210fded3b6212c46bac65ee603d3385.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
Optimizing supply chain network design with location-inventory decisions for perishable items: A Pareto-based MOEA approach
Sadra
Rashidi
Abbas
Saghaei
Seyed Jafar
Sadjadi
Soheil
Sadi-Nezhad
In this paper, a bi-objective mathematical model is presented to optimize supply chain network with location-inventory decisions for perishable items. The goals are to minimize total cost of system including transportation cost of perishable items from centers into DCs, DCs to ultimate center, transportation cost of unusual orders, and fixed cost of centers as DCs as well as demand unresponsiveness. Considering special conditions for holding items, regional DCs, and determining average of life time items assigned to centers are other features of the proposed model. With regard to complexity of the proposed model, a Pareto-based meta-heuristic approach called multi-objective imperialist competitive algorithm (MOICA) is presented to solve the model. To demonstrate performance of proposed algorithms, two well-developed multi-objective algorithms based on genetic algorithm including non-dominated ranked genetic algorithm (NRGA) and non-dominated sorting genetic algorithm (NSGA-II) are applied. In order to analyze the results, several numerical illustrations are generated; then, the algorithms compared both statistically and graphically. The results analysis show the robustness of MOICA to find and manage Pareto solutions.
supply chain network design
Perishable products
location-inventory
Multi-objective optimization
Pareto-based meta-heuristics
2016
12
01
3025
3045
http://scientiairanica.sharif.edu/article_4009_402d08b5af43aef3eb4e6bec7c8cf75f.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
Development of a Joint Economic Lot Size Model with Stochastic Demand Within non-equal shipments
Salman
Barzegar
Mehdi
seifbarghy
Seyed Hamidreza
Pasandideh
Masoud
Arjmand
The majority of the researches in the integrated vendor-buyer inventory problem assume that the shipments are equal. In this paper, shipments are considered to be non-equal. Both demand and delivery times are also assumed to be stochastic. Moreover, unsatisfied demand can be backordered and lost, as well asconsidering a service level constraint. The objective is to minimize both buyer and vendor costs at the same time. The problem is solved by an exact heuristic algorithm. To validate the algorithm’s performance, the results are compared with that of LINGO solver. Finally, a set of numerical problems is applied to compare the result in the integrated and independent forms.
Vendor-Buyer Cooperation
Stochastic demand
Stochastic Delivery Time
Non-equal shipments
exact algorithm
2016
12
01
3026
3034
http://scientiairanica.sharif.edu/article_4010_0ef37365a49bd97570b7be85405f9f79.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
A novel two-stage stochastic model for supply chain network design under uncertainty
M.
Mohajer Tabrizi
B.
Karimi
S.A.
Mirhassani
This paper addresses the problem of designing a supply chain network consisting of suppliers, manufacturers, warehouses, and customers in which all manufacturers belong to a single owner. All players in this chain are performing under uncertainty. The single product of this supply chain needs one strategic and one non-strategic part for its nal assembly. To hedge against uncertainty in supply and demand, the manufacturers tend to take part in a set of suppliers through a portfolio of contracts, and unmet demand will be satised by purchasing from spot market with stochastic prices. In addition, demands, supply capacities, and warehouse capacities are stochastic as well, and the problem has been modeled as a two-stage stochastic program with recourse. Then, a hybrid solution strategy based on sample average approximation and accelerated Benders decomposition is proposed to tackle the problem. The proposed strategy is able to obtain good quality solutions for a large number of scenarios and within an acceptable time interval. Computational results show the eectiveness of the stochastic model as compared to its deterministic counterpart.
supply chain network design
Strategic and non-strategic items
Supplier contracts
uncertainty
Sample average approximation
Two-stage stochastic programming
Benders decomposition
2016
12
01
3046
3062
http://scientiairanica.sharif.edu/article_4011_b8f5290028defe6096e499050daf501d.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
A Geometrical Explanation to the Optimality Concept of Minimum Cost Flows
Mehdi
Ghiyasvand
Shigeno et al.'s algorithm(2000) is a scaling method to solve the minimum cost flow problem. In each phase, they applied the most positive cut canceling idea. In this paper, we present a new approach to solve the problem, which uses the scaling method of Shigeno et al.(2000), but, in each phase, we apply the out-of-kilter idea instead of the most positive cut canceling idea. Our algorithm is inspired by Ghiyasvand(2012). The algorithm gives a geometrical explanation to the optimality concept. For a network with $n$ nodes and $m$ arcs, the algorithm performs $O(log (nU))$ phases and runs in $O(m(m+nlog n)log (nU))$ time (where $U$ is the largest absolute arc bound ), which is $O(m(m+nlog n)log n)$ under the similarity assumption. This time is the running time of the algorithms by Orlincite{O} and Vygencite{V} which are the best strongly polynomial-time algorithms to solve this problem.
Operations research
Network Flows Optimization
The Minimum Cost Flow Proble
2016
12
01
3063
3071
http://scientiairanica.sharif.edu/article_4012_4b9e7302524d0960c3ecc694ae299f55.pdf
Scientia Iranica
Scientia Iranica
1026-3098
1026-3098
2016
23
6
Sample size determination for Cp comparisons
S.M.
Chen
J.T.
Liaw
Y.S.
Hsu
Comparison of quality for products (supplies and goods) is extremely important for manufacturers and consumers. Based on correct comparisons, manufacturers and consumers can nd better suppliers to cooperate and better merchandise to purchase, respectively. Quality is often measured and compared by process capability indices, among which Cp is very eective, simple to apply, and particularly useful for the rst round of comparison. In practice, Cp is unknown and should be estimated from observations. Let dCpi denote the maximum likelihood estimator obtained from normal process, Xi, with index value Cpi; i = 1; 2. If dCp1 >dCp2 with high probability when (1 + )Cp2 Cp1. Given 0 dCp2), we demonstrate how to nd the smallest sample size needed to ensure observing dCp1 > dCp2 with probability greater
Process capability index
Maximum likelihood estimator
Biased estimator
Unbiased estimator
Cp
Cpk
2016
12
01
3072
3085
http://scientiairanica.sharif.edu/article_4013_802163682446b5eba631756cdf6a2ec5.pdf