A Heuristic for flow-shop scheduling with machine bypass

Flow-shop systems with machine bypass represent production approaches currently widely adopted in several industrial fields (i.e. electronic and belt industries). As a consequence of differences in the manufacturing process, in those systems, jobs are not forced to stop by each machine. Moreover, if a job does not need processing on a machine, it can skip that machine and the very job eventually residing there. In this paper, a new heuristic for solving the flow-shop scheduling problem with machine bypass is presented. The algorithm is able to manage several scheduling performance measures, finding a set of non-dominated solutions representing the Pareto front. The heuristic integrates a priority rule and a local search procedure with a Multi Attribute Decision Making (MADM) technique in such a way as to drive the search direction towards good trade-off solutions. To show the effectiveness of the proposed approach some computational results are presented