New heuristics for the no-wait flowshop with sequence-dependent setup times problem

In this paper, we address the problem of scheduling jobs in a no-wait flowshop with sequence-dependent setup times with the objective of minimizing the makespan and the total flowtime. As this problem is well known for being NP hard, we present two new constructive heuristics to obtain good approximate solutions for the problem in a short CPU time, named GAPH and QUARTS. GAPH is based on a structural property for minimizing makespan and QUARTS breaks the problem in quartets to minimize the total flowtime. Experimental results demonstrate the superiority of the proposed approaches over three of the best-known methods in the literature: BAH and BIH, from Bianco et al. (INFOR J 37(1):3–19, 1999) and TRIPS, by Brown et al. (J Oper Res Soc 55(6):614–621, 2004).