It is well-known that simultaneous lot sizing and scheduling is an important instrument in supply chain management. The most common models are based on the assumption of deterministic demand quantities which are given for a fixed point in time. Hence in such a framework there is no flexibility for satisfying this demand with respect to the delivery date. But obviously in real world applications the observed customer behaviour differs significantly from that situation. In fact, often the customer offers an earliest and a latest delivery date.
In this contribution we present a new model that incorporates the aforementioned idea of time windows. This adaption requires a decoupling of demand and delivery. All modifications result in a multi-stage multiproduct simultaneous lot sizing and scheduling with capacity restrictions, setup carry overs, flexible production structures and time windows. Finally, a small numerical example demonstrates the overall benefit of the new approach.