This paper, dealing with discrete production systems, has two goals. The first one is to identify cases in which the use of expert configurator software is a significant improvement for concurrent engineering achievement. Since the industrial implementation of these configurators is often tricky, the second issue of this paper is to present a model that allows to specify the industrial problem before implementation. This paper is divided into three sections. We first quickly recall the main trends of concurrent engineering and the related expert configurator interests. Then, the basic behavior and solutions for expert configurators are presented and the modeling requirements are pointed out. The third part is dedicated to the presentation, illustrated with an example, of our model and our method.