To make an expert system available to the operational managers of the road networks seems to be a well adapted response to the problem: an important economical activity (5 Billions of French Francs per annum, in France), a widely distributed decision making which is not always strictly rational, well known but rarely available experts. Such is the aim of ERASME (Road Maintenance assisted by a Multi Expert System). ERASME assists the operator for the diagnosis and the design of the pavement works for a homogeneous section (a section is homogeneous if all the significant parameters of the problem are sufficiently identical for the whole of this section). ERASME reproduces the thinking of a specialised engineer trying to understand the problem. The questions it asks are not numerous and all to the point. ERASME is able to explain its questions and to justify them for the user. After a diagnosis stage, ERASME establishes work solutions. For an identical diagnosis it proposes several alternatives that will meet the requirements established by the user. If the case arises that missing data or a too complicated problem lead to multiple solutions, ERASME is able to show the way to the user towards the most relevant enquiries (additional visual checks, lab tests) in order to detect the most appropriate medicine, or even, if the case is too complicated, to send the user back to a human expert. ERASME is the result of the work of a multi disciplinary team (computer engineers, experts, users) working under the supervision of Works Leading Committee that gathers executives from the Directorate of Roads, which finances the project, and of future users (District Public Work Directorates, District Technical Services and Motorway Companies). The expertise shown in ERASME is representative of the French abilities and know how in the field of pavement maintenance. Especially, the problem of road maintenance has been broken down into a score of more specialised sub-problems, among which for example; wearing course fatigue, frost, traffic structure adequacy. For each one of these sub-problems, a search was launched, within the lab network, for the specialist likely to supply the highest expertise and his knowledge has been modelized into an expert system. ERASME gathers all these expert systems which work under the authority of a supervisor. ERASME is linked with calculation software used in the field of road maintenance and takes profit from all the advanced technologies in the field of Artificial Intelligence: non monotonous reasoning, multiple states, reasoning on the reasoning, which are integrated into the SMECI generator. ERASME will be available on the 32 bits SUN work stations rigged up with UNIX, Le-Lisp (INRIA) and X-Windows. It is being tested (for flexible pavements only) since June 1989, by some ten pilot users who have the task to detect the last discrepancies of a system that was already widely tested during the second semester of 1988 by six experts. This ultimate tuning is necessary in order to supply the"general public" users with an easy to use product, even for a person not familiar with data processing; the goal aimed at represents about a hundred work locations fitted with the program during the coming two or three years.
Samenvatting