This article focuses on the monitoring of a supply chain dedicated to the mass production of strongly diversi-fied products. Specifically, we are interested in the part of this chain that contributes to the production of a set of alter-native modules assembled on a work station of one or several assembly lines, whose production levels are stable. The MRP approach is adopted for the monitoring of this chain. The distance between the production units leads to a mix between production to stock and production to order. In this article, we establish the relations that allow us to define, in a steady state, the quantities to produce that address the requirements of the Master Production Schedule and that are partially or completely random to limit the stockout risk to a very low predeter