JOBS PRE-ALLOCATION ON PARALLEL UNRELATED MACHINES WITH SEQUENCE DEPENDENT SETUP TIMES: EVIDENCE FROM A LARGE EXPERIMENTATION

In this paper the problem of allocating and scheduling jobs on parallel unrelated machines is studied. Jobs are grouped in families of similar items. A sequence dependent setup is required between batches of jobs belonging to the same and different families, even if in the first case lower time is required. The size of batches is not known a-priori, hence the problem is divided in two different sub-problems: a) the allocation of volumes of work on each machine and b) subsequently the scheduling of each item. The focus of the paper is on the first step and consequently on the pre-assignment problem. Three different solving approaches are implemented in several real-life case studies.