Design and optimization of manufacturing facilities layouts

The present paper deals with the design of manufacturing facilities layout with the consideration of downtime of facilities and space utilization using genetic algorithm (GA). The existing approaches to solve problems of unequal area facility layout in manufacturing environments can provide optimal solutions with limitations such as single design criterion, manual revision, and approximated shape. Also, importance to practical factors such as downtime of facilities owing to planned maintenance or failure of machines, and floor space utilization are addressed to a lesser degree. A mathematical model and a heuristic solution procedure for designing manufacturing facilities layouts that address the above-mentioned shortcomings are proposed. The proposed model minimizes the cost associated with material handling during normal and breakdown periods with due consideration of compactness of the layout. A heuristic placement procedure, which is capable of changing the orientation of facilities, is proposed to place the machines in the floor area, in order to obtain maximum space utilization. The proposed design approach is evaluated by solving different layout design problems taken from the literature and by solving an industrial case study. The results of the proposed GA optimizer are compared with results obtained from greedy search and simulated annealing methods. The results show that the approach performs better in most of the cases.