Dealing with Capacitated Aisles in Facility Layout: A Simulation Optimization Approach

Abstract

In manufacturing systems layout of machines has a significant impact on production time and cost. The most important reason for this is that machine layout impact on transportation time and cost. When designing layout, the aisles structure has an effect on transportation. The aisles are paths that transporters go through them to move the materials between machines. The capacity of the aisles is not infinitive and there is a limitation for the number of transporters that can pass an aisle at the same time. This causes transporters wait for the aisle to be empty or even transporters crossing. Therefore, when optimizing the layout of machines, the aisles structure and their capacity must be investigated. This paper proposes an approach for layout design in manufacturing systems taking into account capacitated aisles structure. First, the aisle structure is determined. Then, the machines are assigned in the possible areas. A simulation optimization approach is proposed to solve the problem. This helps us to avoid unrealistic assumptions and consider realistic conditions such as stochastic characteristics of the manufacturing system, random process time and random breakdown. A genetic algorithm is used to search for the best position of machines. Finally, a numerical example is included to illustrate the proposed approach.