Abstract

In this paper, the two-floor facility layout problem with unequal departmental areas in multi-bay enviro-nments is addressed. A mixed integer programming formulation is developed to find the optimal solu-tion to the problem. This model determines position and number of elevators with consideration of conf-licting objectives simultaneously. Objectives include to minimize material handling cost and to maxi-mize closeness rating. A memetic algorithm (MA), is designed to solve the problem and it is compared with the corresponding genetic algorithm for large-sized test instances and with a commercial linear programming solver solution to small-sized test instances. Computational results proved the efficiency of solution procedure to the problem.

Key words: Mixed integer programming, multi floor layout, multi objective.