Planning of Combined Make-to-Order and Make-to-Stock Production

Production companies face the daily challenge of producing at minimal cost, while they have to fulfill uncertain demand. Companies can choose between two basic strategies to cope with this: produce in advance and deliver products off the shelf (make-to-stock), or produce after products have been ordered (make-to-order). Combining the two strategies in one facility is known as hybrid production. However, because the production planning and control for each of the strategies is very different, it is not at all obvious how it should be organized for the hybrid facility. This thesis deals with this challenge.

For make-to-order, a main challenge of the planning is to realize tight delivery dates. Hence, an order's priority will generally depend on the time until its delivery date. For make-to-stock, the challenge is to keep inventories and accompanying costs low, while maintaining high service rates. The priority of an inventory replenishment order generally depends on the stock level.

Intuitive and popular approaches for hybrid production integrate the planning and control of one order types into the other. However, in doing so, interactions and influences of the hybrid company state are easily overseen. In a number of studies, this thesis shows how the planning of make-to-order and make-to-stock can be integrated in a more flexible manner and that significant cost and/or delivery benefits can be achieved.