Integration of lotsizing and scheduling decisions in a job-shop

In this paper, we consider an integrated model for job-shop lotsizing and scheduling in order to determine a feasible plan, i.e. a plan with at least one feasible schedule. Our method consists in alternatively solving problems at two different levels, one in which lotsizes are computed for a given sequence of jobs on each machine, and one in which a sequence is computed given fixed lotsizes. Different approaches are investigated, and computational results are reported.