Some heuristics for no-wait flowshops with total tardiness criterion

No-wait flowshop scheduling problem is widely investigated because of its practical application and specific properties. However, the total tardiness criterion has not been much considered. In this paper, we propose six heuristic approaches for no-wait flowshops with total tardiness criterion, among which the modified NEH algorithm (MNEH) is verified to be the best. Also, a speed-up technique is introduced to MNEH to reduce the computational time in certain cases. By numeral experiments and analysis, we evaluate the performances of various heuristics. Finally we find out that MNEH is a satisfactory algorithm dealing with this problem.