Pull control systems - The automotive case study

This article is primarily of interest to the assembly industries, which offer a wide variety of finished products, usually described in a specific catalog offered to customers. This is the case in the automotive, mainframe, industrial vehicle, furniture, aeronautics and other industries. The diversity of products is so great as to make sales from stock of finished products either totally impossible (aeronautics) or only partially feasible (automobiles).

The approach consists of directly producing finished products ordered by customers, while respecting a short lead time (one to three weeks, excluding transport in the automotive sector). This lead time is much shorter than the total production lead time, including all supplier procurement lead times (3 to 8 months in the automotive industry).

The method described here is similar to that used and developed by Toyota since the late 1970s. It responds to the problem posed, and nevertheless enables industrial flows to be managed simply and efficiently.

Downstream-controlled flows" are an alternative to traditional methods based on forecast-based production planning (such as MRP, Production Resource Planning).

Although "pull flows" can be applied to a wide range of products and professions, examples taken from the automotive industry, specifically the PSA Group, will illustrate the points made.

Finally, the vocabulary for this method has not yet stabilized, with the following three expressions having the same meaning:

• pull flows ;

• downstream-driven flows ;

• short lead-time production.

The expression "downstream-driven flows" best illustrates the basic principles of this method.