Configuring layout in unidirectional loop manufacturing systems

This paper addresses the layout configuration problem of workstations in a unidirectional loop manufacturing system. In this popular unicyclic materia l handling facility, the material transporters depart from the input/output station, traverse each workstation exactly once, and then return to the in put/output station. We show the important properties of this unidirectional material handling loop network. Based on these characterizations, both heu ristic and branch- and bound algorithms are proposed to solve such NP-compl ete layout problems. Computational experiments with problem sizes up to 100 workstations are reported. Both the problem size and the material flow den sity have been found to affect the solution quality and the computational e fficiency. The proposed methods appear efficient and effective for solving these layout problems.