A discussion of production planning approaches in the process industry

In this paper, we discuss the literature on production planning approaches in the process industry. Our contribution is to underline the differences, as well as the similarities, between issues and models arising in process environments and better known situations arising in discrete manufacturing, and to explain how these features affect the optimization models used in production planning. We present an overview of the distinctive features of process industries, as they relate to productionplanning issues. We discuss some of the difficulties encountered with the implementation of classical flow control techniques, like MRP or JIT, and we describe how various authors suggest to solve these difficulties. In particular we focus on the concept of "recipe", which extends the classical Bill of Materials used in discrete manufacturing, and we describe how the specific features of recipes are taken into account by different production planning models. Finally,we give a survey of specific flow control models and algorithmic techniques that have been specifically developed for process industries.