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Modarres M.,Sharif University of Technology | Sadi-Nezhad S.,Islamic Azad University at Tehran | Arabi F.,Industrial Management Institute
International Journal of Industrial Engineering Computations | Year: 2010

Analytic Hierarchy Process (AHP) is one of the most popular approaches in the area of multiple attribute decision making (MADM). However, it is not practical any more if input information are fuzzy. In this paper, we propose a new method for fuzzy AHP which is especially useful to make decisions for multiple attribute problems. The method is developed by applying preference ratio concept which makes it practical since it assigns crisp weights and crisp scores to different alternatives. Two algorithms are proposed in this paper: The first one defines crisp and normalized weight by pairwise comparison with fuzzy data while the second one calculates fuzzy consistency ratio. The proposed method is applied to prioritize different short courses in a management school. © 2010 Growing Science Ltd. All rights reserved.

Khalili-Damghani K.,Islamic Azad University at Tehran | Tavana M.,Philadelphia University | Tavana M.,University of Paderborn | Najmodin M.,Industrial Management Institute
International Journal of Industrial Engineering : Theory Applications and Practice | Year: 2015

The process of transforming raw materials into final products and delivering those products to customers, known as supply chain (SC) management, is becoming increasingly complex. Most of SC management research has been concerned with procurement and production. However, recently, it has become increasingly important to extend SC issues beyond the point of sale to reverse logistic (RL) where the flow of returned products is processed from the customers back to the collection centers for repair, remanufacturing or disposal. We propose a conceptual framework and empirically investigate the relationship between the key factors in RL and SC performance measurement using a series of hypotheses. Structural equation modeling (SEM) is used to test the hypotheses. The results reveal insightful information about the effects of RL factors on the SC performance. © INTERNATIONAL JOURNAL OF INDUSTRIAL ENGINEERING.

Pashang Pisheh Y.,Amirkabir University of Technology | Shafiei H.R.,Industrial Management Institute | Hatambeigi M.,Imam Khomeini International University
Forensic Engineering, Proceedings of the Congress | Year: 2010

One of the major reasons for disasters during construction of massive concrete structures is the failure of weak and defective scaffolding systems. During the construction of Bojnourd cement factory, the failure of forming system related to the concrete slab of the bypass clinker silo led to collapse and crush of the fresh concrete slab and death and injury of some labors in the site. In this paper, using in-situ and numerical investigations, the main causes of the accident are studied. So, by making use of Finite Element Method, the forming system including scaffold grids has been modeled and analyzed respected to common and extra loading applied on the elements. Various analyses were carried out in existence and absence of the proper lateral bracing system considering P-Delta effects in scaffolding elements. Based on the current study, application of improper connections in vertical elements of scaffolding piers, weak lateral bracings in two orthogonal directions, and discontinuity in scaffolding performance were distinguished as the main reasons for occurrence of this destructive event.

Teimoury E.,Iran University of Science and Technology | Teimoury E.,Institute for Trade Studies and Research | Modarres M.,Sharif University of Technology | Ghasemzadeh F.,Industrial Management Institute | And 2 more authors.
Journal of Manufacturing Systems | Year: 2010

In some industries such as the consumable product industry because of small differences between products made by various companies, customer loyalty is directly related to the availability of products required at that time. In other words, in such industries demand cannot be backlogged but can be totally or partly lost. So companies of this group use make-to-stock (MTS) production policy. Therefore, in these supply chains, final product warehouses play a very important role, which will be highlighted by considering the demand uncertainty as it happens in real world, especially in the consumable product industries in which demand easily varies according to the customer's taste variation, behavioral habits, environmental changes, etc. In this article, an (s,Q) inventory system with lost sales and two types of customers, ordinary and precedence customers and exponentially distributed lead times are analyzed. Each group of demands arrives according to the two independent Poisson processes with different rates. A computationally efficient algorithm for determining the optimal values for safety stock as reorder level and reorder quantity for a multi-item capacitated warehouse is developed. The algorithm also suggests the optimal warehouse capacity. A Multi-item Capacitated Lot-sizing problem with Safety stock and Setup times (MCLSS) production planning model is then developed to determine the optimal production quantities in each period using optimal values computed by the first algorithm as inputs. Finally, the proposed production-inventory-queue model is implemented in a case study in PAKSHOO Chemicals Company and results are obtained and analyzed. Moreover, solving this problem can help to strategic decision making about supply chain decoupling point. © 2010 Published by Elsevier Ltd on behalf of The Society of Manufacturing Engineers. All rights reserved.

Khalili-Damghani K.,University of Tehran | Aminzadeh-Goharrizi B.,Imam Khomeini International University | Rastegar S.,Industrial Management Institute | Aminzadeh-Goharrizi B.,Industrial Management Institute
International Journal of Geographical Information Science | Year: 2014

The aim of Land-use Suitability Analysis and Planning Problem (LSAPP) is to identify the most suitable parcels of land for future land-uses considering several conflicting criteria. LSAPP can be modeled using a variant of a well-known combinatorial optimization problem called Quadratic Assignment Problem (QAP). In this paper, a multi-objective mathematical model is developed for LSAPP based on QAP modeling. The large-size instances of the proposed multi-objective mathematical model are difficult to solve in a reasonable CPU time using exact algorithms. So, an efficient three-phase hybrid solution procedure is proposed. In the first phase, the compensatory objectives are integrated using Analytic Hierarchy Process (AHP) and Decision-Making Trial and Evaluation Laboratory. Then, based on the aforementioned suitability objective function and other spatial objectives and constraints, a multi-objective LSAPP is constructed. Finally, a hybrid multiple objective meta-heuristic algorithm is proposed to solve the LSAPP. The core of the proposed algorithm is based on Scatter Search while Tabu Search and Variable Neighborhood Search are also utilized. The proposed algorithm is equipped with the concepts of Pareto optimality and Veto Threshold, which improve its efficacy. The proposed algorithm is applied on a real LSAPP case study, in ‘Persian Gulf Knowledge Village’, wherein its performance is compared with a well-known evolutionary computation algorithm called Vector Evaluated Genetic Algorithm (VEGA) using comprehensive statistical analysis. A survey on time complexity of the proposed algorithm is also accomplished. The results show that MOSVNS is significantly superior to VEGA both in single and in multi-objective modes. Furthermore, analysis of time complexity of the proposed algorithm shows that it is of polynomial time and can be applied to significantly larger problems with multiple compensatory and non-compensatory objectives. © 2014 Taylor & Francis.

Khalili-Damghani K.,University of Tehran | Shahmir Z.,Industrial Management Institute
Computers and Industrial Engineering | Year: 2015

In this paper, a customized network data envelopment analysis model is developed to evaluate the efficiency of electric power production and distribution processes. In the production phase, power plants consume fuels such as oil and gas to generate the electricity. In the distribution phase, regional electricity companies transmit and distribute the electricity to the customers in houses, industries, and agriculture. Although, the electricity is assumed to be a clean type of energy, several types of emissions and pollutions are produced during electricity generation. The generated emissions are considered as an undesirable output. A customized network data envelopment analysis (NDEA) approach is proposed to evaluate the efficiency of these processes Each decision making unit (DMU) includes two serially connected sub-DMUs, i.e., production and distribution stages. The models are extended using interval data to address the considerable uncertainty in the problem. The efficiency scores of main process, and each sub-process are determined. The final ranking of DMUs and sub-DMUs are achieved using a multi-attribute decision making (MADM) method. The whole approach is applied in a real case study in electrical power production and distribution network with 14 DMUs. The proposed approach has the following innovations in comparison with existing methods: (1) Both production and distribution process are evaluated in a unique model; (2) Undesirable outputs and uncertainty of data are considered in proposed approach; (3) Properties of proposed models are discussed through several theorems; (4) The efficiencies of production and distribution phases are determined distinctively; (5) A full ranking approach is proposed; (6) A real case study of electrical power production and distribution network is surveyed. The results of proposed approach are adequate and interesting. This approach can be customized for application in similar systems such as water production-supply management, Oil and fuel production-distribution systems, and supply chains. © 2015 Elsevier Ltd. All rights reserved.

Sotoudeh-Anvari A.,Industrial Management Institute
Journal of Intelligent and Fuzzy Systems | Year: 2016

Comparing fuzzy numbers is a key task in decision making. Although, up to now several techniques have been introduced for ordering fuzzy numbers, nearly all of these methods contain various defects. In this paper, we introduce a new approach for ranking generalized trapezoidal fuzzy numbers. The suggested technique combines the trait of two ideas namely positive and negative ideal points as well as the centroid point. This method is logically easy and has very straightforward computation. The benefits of the proposed method are discussed through a number of comparative numerical cases. © 2016 - IOS Press and the authors. All rights reserved.

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