An integrated approach for the concurrent determination of the block layout and the input and output point locations based on the contour distance

This paper presents an integrated approach for the facilities design problem. It develops a method for the concurrent determination of the block layout, the locations of departmental input and output (I/O) points using the contour distances between the I/O points, and the material flow paths between the I/O points. The topology of block layouts is represented using two linear sequences (sequence-pair), which allows the layout to have either a slicing or a non-slicing structure. The block layout is obtained from the sequence-pair with a linear programming formulation. Three heuristic methods are then presented to determine for a given block layout the locations of the I/O points on the perimeters of the departments. The flow paths from output to input points are found by determining the shortest paths that follow the perimeters of the departments. The linear programming algorithm, the shortest path algorithm, and the I/O point location heuristics are embedded into a simulated annealing algorithm that modifies the sequence-pair to obtain a high-quality layout based on the contour distances between the I/O points. Results of computational experiments show that the performance of this integrated algorithm compares favourably with those of algorithms using a sequential approach and is capable of solving industrial-sized problems in acceptable computation time.