Journal of Industrial Engineering International: 4 (11)

Open Access Article

1 - Assembly line balancing to minimize balancing loss and system loss
D Roy D Khan

Assembly Line production is one of the widely used basic principles in production system. The problem of Assembly Line Balancing deals with the distribution of activities among the workstations so that there will be maximum utilization of human resources and facilities More

Assembly Line production is one of the widely used basic principles in production system. The problem of Assembly Line Balancing deals with the distribution of activities among the workstations so that there will be maximum utilization of human resources and facilities without disturbing the work sequence. Research works reported in the literature mainly deals with minimization of idle time i.e. balancing, subject to precedence constraints. Lack of uniqueness in their optimum solutions has led to the present work where minimization of both balancing loss and system loss has been envisaged under the usual precedence constraints. The researchers suggest a generic approach for designing of an assembly line where, with a given number of workstations, one can efficiently arrive at the desired solution under different methods of search like simulation, heuristic etc. Thus, the main aim of this paper is to redefine the objective of the Assembly Line Balancing Problem and sequentially handle Balancing Loss and System Loss. A numerical example has been added to demonstrate the generic nature of the researcher's approach and improvement in the solution set when compared with different standard line balancing methods available so far in the literature. Manuscript profile

Open Access Article

2 - A redundancy allocation problem with the choice of redundancy strategies by a memetic algorithm
J Safari R Tavakkoli-Moghaddam

This paper proposes an efficient algorithm based on memetic algorithm (MA) for a redundancy allocation problem without component mixing (RAPCM) in a series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution met More

This paper proposes an efficient algorithm based on memetic algorithm (MA) for a redundancy allocation problem without component mixing (RAPCM) in a series-parallel system when the redundancy strategy can be chosen for individual subsystems. Majority of the solution methods for the general RAPCM assume that the type of a redundancy strategy for each subsystem is pre-determined and known a priori. In general, active redundancy has traditionally received greater attention; however, in practice both active and cold-standby redundancies may be used within a particular system design. The choice of the redundancy strategy then becomes an additional decision variable. Thus, the problem is to select the best redundancy strategy, component and redundancy level for each subsystem in order to maximize the system reliability under system-level constraints. Due to its complexity and NP-hardness, it is so difficult to optimally solve such a problem by using traditional optimization tools. To validate the performance of the proposed MA in terms of solution quality, a number of test problems are examined and the robustness of this algorithm is then discussed. Finally, the related results are reported and it is shown that the proposed MA performs well. Manuscript profile

Open Access Article

3 - Fuzzy completion time for alternative stochastic networks
S.S Hashemin

In this paper a network comprising alternative branching nodes with probabilistic outcomes is considered. In other words, network nodes are probabilistic with exclusive-or receiver and exclusive-or emitter. First, an analytical approach is proposed to simplify the struc More

In this paper a network comprising alternative branching nodes with probabilistic outcomes is considered. In other words, network nodes are probabilistic with exclusive-or receiver and exclusive-or emitter. First, an analytical approach is proposed to simplify the structure of network. Then, it is assumed that the duration of activities is positive trapezoidal fuzzy number (TFN). This paper combines the randomness and fuzziness and shows that the fuzzy completion time of alternative stochastic network is a fuzzy-valued random variable. Then, the probability function of network fuzzy completion time and its expected value is defined. Finally, the applications and computations are illustrated in a numerical example. Manuscript profile

Open Access Article

4 - A profit Malmquist productivity index
GH Tohidi SH Razavyan S Tohidnia

In some situations the producers desire to maximize total profit of Decision Making Units (DMUs) while the inputs and outputs prices of DMUs change from one time period to another. In this paper, the researchers develop productivity index when producers are going to max More

In some situations the producers desire to maximize total profit of Decision Making Units (DMUs) while the inputs and outputs prices of DMUs change from one time period to another. In this paper, the researchers develop productivity index when producers are going to maximize total profit when the price of inputs and outputs are known.The proposed method uses all price information about inputs and outputs for determining productivity index while previous methods use only cost of inputs to determine index of productivity .Therefore, the proposed Mulmquist productivity index in this paper is more precise than the other Mulmquist productivity index. Here, productivity change is decomposed into profit efficiency and profit technical change. Furthermore, profit efficiency change is decomposed into technical and allocative efficiency change and profit technical change into a part capturing shifts of input and output quantities and shifts of input and output prices. These decompositions provide a clearer picture of the root sources of productivity change. Finally, the proposed fractional programming problems are converted to the linear programming problems. By an illustrative example, we explain the proposed profit Malmquist productivity index. Manuscript profile

Open Access Article

5 - A graphical instrument for performance analysis of contractors
K.T Yu C.Y Shen D.K Huang

The relationship between the manufacturer and supplier has changed from one of competition into that of greater cooperation during recent years. The selection and evaluation of suppliers are primary and important issues when an enterprise implements Supplier Relationshi More

The relationship between the manufacturer and supplier has changed from one of competition into that of greater cooperation during recent years. The selection and evaluation of suppliers are primary and important issues when an enterprise implements Supplier Relationship Management (SRM) and Total Quality Management (TQM). Much research indicates that most enterprises tend to evaluate their suppliers based largely on quality, delivery, and price performance. However, an analysis tool which can simultaneously integrate numerical decision criteria is rare, especially those suitable for evaluating various operational aspects, such as industry categories, purchase types, or production strategies. Based on this reason, an integrated model using multiple performance indices to construct a supplier performance evaluation chart (SPEC) is presented in this study. It is a graphic portrayal that can simultaneously display each supplier’s performance of quality, delivery, and price through the use of a categorical symbol and its location on the SPEC. Based on the expected levels for each evaluation criteria, the manager can mark a target region on the SPEC so that an existing or new supplier’s ability to achieve the preset level is effectively and conveniently indicated. Finally, an illustration is provided as a practical application. Manuscript profile

Open Access Article

6 - Yard crane scheduling in port container terminals using genetic algorithm
H Javanshir S.R Seyedalizadeh Ganji

Yard crane is an important resource in container terminals. Efficient utilization of the yard crane significantly improves the productivity and the profitability of the container terminal. This paper presents a mixed integer programming model for the yard crane scheduli More

Yard crane is an important resource in container terminals. Efficient utilization of the yard crane significantly improves the productivity and the profitability of the container terminal. This paper presents a mixed integer programming model for the yard crane scheduling problem with non- interference constraint that is NPHARD in nature. In other words, one of the most important constraints in this model which we can mention to yard crane non- interference constraint is that they usually move on the same rails in the yard block. Optimization methods, like branch and bound algorithm, has no sufficient efficiency to solve this model and become perfectly useless when the problem size increases. In this situation, using an advanced search method like genetic algorithm (GA) may be suitable. In this paper, a GA is proposed to obtain near optimal solutions. The GA is run by MATLAB 7.0 and the researchers used LINGO software which benefits from the Branch and Bound algorithm for comparing outputs of GA and the exact solution. We should consider the abilities of the LINGO software which is not capable of solving the problems larger than 5 slots to 3 yard cranes. The computational results show that the proposed GA is effective and efficient in solving the considered yard crane scheduling problem. Manuscript profile

Open Access Article

7 - Dynamic modeling to determine production strategies in order to maximize net present worth in small and medium size companies
B Kiyani P Shahnazari Shahrezaei H Kazemipoor M Fallah

Determining production rate considering costs and revenues in order to maximize profit is one of the applied problems in small and medium size factories. Mostly existing models in production planning consider production system statically and specify production rate, alt More

Determining production rate considering costs and revenues in order to maximize profit is one of the applied problems in small and medium size factories. Mostly existing models in production planning consider production system statically and specify production rate, although the factors determining production rate include many different changes in practice. In fact, by increasing the production rate or mass production, production costs can be reduced. Costs reduction will result in sales price falling. Then, sales price will affect the demand and demand can increase. Demand increase will lead to more income and this process will repeat again. In this paper, a model will be proposed for production system of small and medium size companies regarding costs, revenues and dynamic reaction of systems against changes, by applying system dynamics and Vensim software. Since Iran is a developing country, the model will be analyzed and validated for a medium size factory and then some policies will be presented to improve the factory situation in the future. Manuscript profile

Open Access Article

8 - Determining maintenance system requirements by viewpoint of availability and lean thinking: A MODM approach
S Ghayebloo H Babaei

Since lean concept has appeared many works have been done on decreasing or even eliminating of wastes such as extra inventory. Although these studies have not taken into account expected availability seriously. So in this paper, a Multiple Objective Decision Making (MOD More

Since lean concept has appeared many works have been done on decreasing or even eliminating of wastes such as extra inventory. Although these studies have not taken into account expected availability seriously. So in this paper, a Multiple Objective Decision Making (MODM) model has been developed by viewpoint of these subjects. They are decreasing wastes and increasing system availability. Wastes that have been minimized are maintenance requirements (i.e. labor, spare parts, reserve system and productive maintenance activities) and maintenance system availability that has been maximized is a function of maintenance requirements. A set of Society Anonym Iranian Production Automobile (SAIPA) data has been used to run the case study and test the effectiveness and the efficiency of the proposed model. Manuscript profile

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