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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Optimization in Industrial Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Sequencing problem,Two-sided assembly line,Mixed model assembly line,Make to order
- چکیده:
- چکیده انگلیسی: Mixed model two-sided assembly lines (MM2SAL) are applied to assemble large product models, which is produced in high-volume. So, the sequence planning of products to reduce cost and increase productivity in this kind of lines is imperative. The presented problem is tackled in two steps. In step 1, a framework is developed to select and prioritize customer orders under the finite capacity of the proposed production system. So, an Analytic Network Process (ANP) procedure is applied to sort customers’ order based on 11 assessment criteria. In step 2, a mathematical model is formulated to determine the best sequence of products to minimize the total utility work cost, total idle cost, tardiness/earliness cost, and total operator error cost. After validation of the presented model using GAMS software, according to the NP-hard nature of this problem, a genetic algorithm (GA) and particle swarm optimization (PSO) are used. The performance of these algorithms are evaluated using some different test problems. The results show that the GA algorithm is better than PSO algorithm. Finally, a sign test for the two metaheuristics and GAMS is designed to display the main statistical differences among them. The results of the sign test reveal GAMS is an appropriate software for solving small-sized problems. Also, GA is better than PSO algorithm for large sized problems in terms of objective function and run time.
- انتشار مقاله: 21-08-1395
- نویسندگان: Masoud Rabbani,Leyla Aliabadi,Hamed Farrokhi-Asl
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial and Systems Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Genetic Algorithm,Life cycle assessment,Energy Consumption,Demand side management
- چکیده:
- چکیده انگلیسی: The main aim of this paper is to select the best portfolio of renewable energy technologies (RETs) for electrifying an elected area which is not connected to any other grids. Minimizing total costs of the system is considered as the main factor in finding the best decision. In order to make the optimum plan more applicable, the technique of life cycle analysis is applied. This technique takes into account all costs of the system from the manufacturing stage of the different parts of a power plant until their disposal. Also, demand-side management alternatives are considered as competing solutions against the mentioned supply side options. To tackle the problem, an integrated and complex mathematical formulation is developed for finding the optimum energy plan regarding the real world assumptions. For the reason of NP-hard nature of the proposed model and it is hard-to-solve for real large sized problems, a genetic algorithm (GA) approach is additionally developed for solving the mixed integer non-linear model for the medium and large size problems. To evaluate the performance of the proposed GA, a range of random test problems are conducted. The obtained results show that the length of planning period is the core factor in selecting the appropriate portfolio of RETs. Furthermore, it is shown that the proposed GA is capable of producing good results in almost negligible processing times.
- انتشار مقاله: 04-10-1394
- نویسندگان: Masoud Rabbani,Ali Keshvarparast,Hamed Farrokhi-Asl
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: Project management,Mathematical Programming,R and D Project Portfolio Selection
- چکیده:
- چکیده انگلیسی: Technology centered organizations must be able to identify promising new products or process improvements at an early stage so that the necessary resources can be allocated to those activities. It is essential to invest in targeted research and development (R and D) projects as opposed to a wide range of ideas so that resources can be focused on successful outcomes. The selection of the most appropriate projects is the aim of R and D project selection models. The project selection is complicated by many factors, such as vision and preferences of decision makers, allocating the right human resources, interrelationships between projects, and changes over time and success factors that are difficult to measure. In this article we formulate essential factors in R and D project portfolio selection by a mathematical model, which consider a multi- objective function for maximizing corporate benefit through quantitative and qualitative criteria as well as insight and preferences of decision makers and human resource allocation which does not exceed organizations constraints such as planning horizon, available resources and interrelationships between projects.
- انتشار مقاله: 11-10-1348
- نویسندگان: H.R. Ghorbani,Fariborz Jolai,Reza Tavakkoli-Moghaddam,Masoud Rabbani
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: approximation,completion time,PERT,Most Critical Path,Stochastic Network,distribution function
- چکیده:
- چکیده انگلیسی: The classical PERT approach uses the path with the largest expected duration as the critical path to estimate the probability of completing a network by a given deadline. However, in general, such a path is not the most critical path (MCP) and does not have the smallest estimate for the probability of completion time. The main idea of this paper is derived from the domination structure between paths that was presented by Soroush for the first time. This paper develops this domination structure and its properties, which make Soroush’s algorithm work faster in some cases. Then a labeling algorithm is presented that is able to compute the MCP from starting node of the network to any node of the network. Also, suitable and practical completion time distribution function estimation is defined. In many cases, the estimation is obtained by the developed method is better than that of Soroush’s. To clarify the point, some examples are given. Finally, conclusions are presented.
- انتشار مقاله: 11-10-1348
- نویسندگان: Masoud Rabbani,S. M. T. Fatemi Ghomi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Engineering, Transactions A: Basics
- نوع مقاله: Journal Article
- کلمات کلیدی: Fuzzy theory,multi,Objective Cell Formation Problem,Dynamic CMS
- چکیده:
- چکیده انگلیسی: This paper proposes a comprehensive, multi-objective, mixed-integer, nonlinear programming (MINLP) model for a cell formation problem (CFP) under fuzzy and dynamic conditions aiming at: (1) minimizing the total cost which consists of the costs of intercellular movements and subcontracting parts as well as the cost of purchasing, operation, maintenance and reconfiguration of machines, (2) maximizing the preference level of the decision making (DM) and (3) balancing intracellular workload. Dynamic CFP divides the planning horizon to smaller periods and considers different product combinations and demands in each period, which may result in cell reconfiguration necessity. Moreover, it is more realistic to take into account the inexact and uncertain (fuzzy) nature of parameters, such as product demand or machine capacity. The main goals of the proposed model is to select a process plan with the minimum cost and also to identify the most appropriate production volume with respect to fuzzy demands and capacities in order to minimize the deviation from the desired production and balanced machine workload.
- انتشار مقاله: 11-10-1348
- نویسندگان: S. Minaeian,Reza Tavakkoli-Moghaddam,Masoud Rabbani
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Industrial Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: optimization,Cross-training,Health care systems,Staff assignment
- چکیده:
- چکیده انگلیسی: In this paper, the staff assignment problem considering cross-training of caregivers in health care systems is addressed to determine which staff should be cross-trained for each service and how they should be assigned to services. A bi-objective non-linear mathematical programming model is presented where the first objective function aims to minimize workload balancing, cross-training as well as maintenance and transportation costs, while the second objective function is concerned with maximization of caregivers’ satisfaction level. Several constraints with respect to budget capacity, staff absenteeism, maximum allowable consecutive shifts, multi-functionality and redundancy level and maximum allowable distance for transportation are taken into account to build a service plan. The behavior of the various elements and features of the model is evaluated in a real-world HC provider and the results reveal that the caregivers’ workload is relatively balanced and the caregivers’ preferences are satisfied.
- انتشار مقاله: 12-05-1394
- نویسندگان: Hamed Habibnejad,Masoud Rabbani,Babak Javadi,Nastaran Ghorbani-Kutenaie
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Industrial Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Customer Satisfaction,pricing,Product characteristics,Product positioning
- چکیده:
- چکیده انگلیسی: This paper addresses a new product positioning problem, in which prices of the products are simultaneously determined in order to maximize both customer satisfaction and seller’s net profit. In this regard, customer willingness is identified with respect to the products within a family, upon which prices of the products are optimized so as to attain two objective functions: 1) maximizing customer satisfaction and 2) maximizing seller’s net profit. Despite of the literature body which has taken this problem into account for a single product, the developed model in this paper considers the case of a multiple products for different customer segments. To do so, an algorithm is developed which the considered problem is divided into a number of sub-problems solved by using GAMS and Matlab. Finally, a numerical example is illustrated.
- انتشار مقاله: 26-11-1393
- نویسندگان: Masoud Rabbani,Hamed Rafiei,Emad Sane Zerang
- مشاهده