The general lotsizing and scheduling problem

The GLSP (ℝ5General ℝ5Lotsizing and ℝ5Scheduling ℝ5Problem) addresses the problem of integrating lotsizing and scheduling of several products on a single, capacitated machine. Continuous lotsizes, meeting deterministic, dynamic demands, are determined and scheduled with the objective of minimizing inventory holding costs and sequence-dependent setup costs. As the schedule is independent of predefined time periods, the GLSP generalizes known models using restricted time structures. Three variants of a local search algorithm, based on threshold accepting, are presented. Computational tests show the effectiveness of these heuristic approaches and are encouraging for further extensions of the basic model.