AbstractThe assignment of empty railcars by the SNCF (French Railways) distributors according to supply and demand from the regions could be considered as a conventional resource allocation problem. As such, it would be suitable for processing by integer programming. However, as the problem is currently solved by the reasoning process of the distributors, it involves much more strategic knowledge than linear programming. Based on this observation, we developed an allocation system centred on an expert system designed to reproduce the reasoning processes of the distributors. This paper describes the system, and the reasons why the ES approach seems more adapted to the problem than the OR pure solution.