We present a new model formulation for lot-sizing and scheduling of multi-stage flow lines which works without a fixed lead-time offset and still guarantees a feasible material flow. In the literature, multi-stage lot-sizing model formulations often use a fixed lead time offset of one period...

A pharmaceutical company raised the question whether an increased product portfolio could still be manufactured on the existing machinery. The proportional lot-sizing and scheduling problem (PLSP) seemed to be most appropriate to answer this question. However, although there are papers dealing...