PURPOSE: To obtain an optimum solving suggestion by analyzing the interrelationships between the production process condition data turned into a data base and various data to be evaluated for generation of the process condition candidates and evaluating totally these candidates together with those process condition candidates generated from the knowledges of experts.

CONSTITUTION: A suggestion generating means 1 generates the process condition candidates from various data inputted in relation to the evaluating subjects prepared for solution of problems by means of a knowledge base 4 storing the knowhows of experts. At the same time, the past production process conditions and various data to be evaluated are stored in a data base 5. A suggestion generating means 2 obtains the interrelationships between the production process condition data stored in the base 5 and various data to be evaluated by an optional analyzing method. Based on these interrelationships, the process condition candidates are generated. Then the process condition candidates generated by both means 1 and 2 are totally evaluated by a suggestion evaluation means 3. As a result, the optimum process conditions are obtained.