Abstract: A quality assurance expert system, ZJSYS, has been developed for car cylinder casting by use of artificial intelligence technology and C++ for windows. The important feature of this expert system is that it draws not only qualitative conclusions but also quantitative ones in the therapy of defects. ZJSYS uses an expert reasoning strategy based on the rule models with the certainty factor. Reasoning strategy combines forward chaining and backward chaining together to perform qualitative analysis of defects. Meanwhile quantitative analysis of defects is completed by use of mathematical statistics and the principle of optimum. Management system that possesses the functions of adding, modifying and deleting was developed in knowledge base. To meet the practical requirements, the management model of data storage and statistics were developed. Actual run of ZJSYS showed that it played a significant role in improving product quality and reduce rejection ratio.

Key words:  cylinder casting; quality assurance; expert system