Flowshop with additional resources during setups: Mathematical models and a GRASP algorithm

Machine scheduling problems arise in many production processes, and are something that needs to be consider when optimizing the supply chain. Among them, flowshop happen a number of jobs have sequentially processed by machines. This paper addressees, for first time, Permutation Flowshop Scheduling problem with additional Resources during Setups (PFSR-S). In this problem, addition standard permutation constraints, each machine requires setup between processing two consecutive jobs. A scarce resources, e.g. operators, needed carry out setup. Two Mixed Integer Linear Programming formulations an exact algorithm proposed solve PFSR-S. Due its complexity, these approaches can only instances small size optimality. Therefore, GRASP metaheuristic is also which provides solutions much larger instances. All methods designed PFSR-S computationally tested over benchmark adapted from literature. The results obtained show finds good quality short computational times.