An efficient algorithm for unequal area facilities layout planning with input and output points

The facility layout problem is to determine a layout design of facilities so as to minimize a total material handling cost (TMHC). In this paper, unequal area rectangular facilities with fixed dimensions are considered. Each of them has an input and output (I/O) points which can be located within or on the boundaries of facility. On the continual plane, facilities must be placed without overlaps. A two-heuristic algorithm is proposed to deal with this kind of problem. The first step is based on a construction method which places facilities sequentially. A median method is modified to set the position of facility. The second step improves a result of the first step. A facility group which can be moved horizontally or vertically without incurring an overlap is constituted and a group movement is done when it reduces a TMHC. Computational experiments show the proposed algorithm produces comparable quality of layouts to previous research within much shorter time.