We study two different lot-sizing problems with time windows that have been proposed recently. For the case of production time windows, in which each client specific order must be produced within a given time interval, we derive tight extended formulations for both the constant capacity and...

We consider the single item lot-sizing problem with capacities that are non-decreasing over time. When the cost function is i) non-speculative or Wagner-Whitin (for instance, constant unit production costs and non-negative unit holding costs), and ii) the production set-up costs are...

The logic of Manufacturing Resource Planning (MRP II) is usually implemented in production planning and control systems and therefore has a major impact on the performance of many real production systems. Much of what practitioners complain about, i.e. long lead times, high work-in-process, and...