The problem of the machine layout inside manufacturing cells (intra-cell layout problem) of an automated manufacturing system is addressed in this paper. The solution presented is divided into two main steps. The first step consists of selecting the materials handling system and the possible machine layout type. This procedure is based on the characteristics of : products (which belong to the same product family), their manufacturing processes and machines. An expert system has been developed for this part. The second step consists of evaluating the alternative arrangements of the machines inside the manufacturing cell in order to minimize the intra-cell traffic (costs) while respecting the physical constraints between the machines, between the machines and their environment, product constraints, technological contraints, user preference, etc. This part is performed using operations research algorithms.