Improved heuristics algorithms for re-scheduling flexible job shops in the era of Zero Defect manufacturing

Zero Defect Manufacturing concept imposes that any event in the production should have a counter-action in order to mitigate it. This approach creates the need for more frequent re-scheduling of the shop floor to accommodate corrective actions. This paper focuses on the improvement of the quality in the flexible job-shop scheduling problem. As stated in the literature, the problem is NP-Hard and therefore approximate approaches are the only option for having a solution. In the current research a metaheuristic method, Tabu search, has been used for the optimization. The current research work focuses on the creation of multiple initial solutions, using different methods and study the quality of the final solution. The simulation results showed that the tweaked version of the Earliest Completion Machine heuristic rule produced the best results and that the final solution was heavily depending on the quality of the initial solution. (C) 2020 The Authors. Published by Elsevier Ltd.