This paper describes the development of an expert system with producti
on rules and the integration of fuzzy techniques (fuzzy rules and fuzz
y data calculus). This system is made for the preliminary design. Fund
amentally, this system is able to accommodate both imprecision and unc
ertainty. We apply this to the breaking chamber of a circuit breaker.
This original approach allows us to use a more systemic approach of th
e design.