In general, a set of optimum molding conditions for manufacturing conforming articles are set by the method of trial and error before mass-producing molded articles. More specifically, one or more molding conditions are modified depending on the type and degree of a molding defect of the molded articles occurred in a molding cycle tried under provisional molding conditions, and the molding cycle is executed repeatedly until the optimum molding conditions are obtained. However, a number of molding conditions are concerned in the molding cycle which is composed of a series of processes such as injection, dwell, metering, etc. Besides, the molding conditions interact with one another. Thus, setting the optimum molding conditions requires much time and labor, as well as skill.
These problems may be solved by constructing a conventional expert system, such as a troubleshooting system, which is comparable to an expert in problem solving capability. It is difficult, however, to put the expert system to practical use, and correction or modification of the system in practical use is a laborious work. Moreover, in some cases the system requires reconstruction. Having these problems on application, the expert system cannot be easily utilized for injection molding.