Customer specific requirements is one of the key drivers in a supply chain strategy based on mass customization. At the same time there are intense pressure on price and short delivery lead times providing a complex environment for managing the supply chain. The complexity can be reduced by introducing the concept of a customer order decoupling point (CODP). The CODP separates the supply chain into two key processes that can be categorized as make-to-order (MTO) and make-to-stock (MTS) and constitutes the two key building blocks of a system based on the mass customization concept. The dynamic properties of the MTS environment have been extensively researched using the automatic pipeline-, inventory-, and order-based production control system (APIOBPCS) archetype. In contrast to MTS systems, the customer facing MTO process, which is usually exposed to a more volatile demand stream suitable for an agile strategy, is less well investigated. Agility does, however, frequently not mean that infinite capacity is available but that there is some surplus capacity available and that the capacity can be adapted to the customer requirements in certain time frames. When the adaptation is not instant but requires some time to take effect the delay creates a dynamic backlog represented by the order book which affects the delivery lead time. Since controlling lead times is a key factor in providing reliable delivery promises an order book control logic is introduced. It is also shown that the new MTO model of the customer facing part of a mass customization system is an extension to the well established APIOBPCS framework.