An expert system to assist production planning

Describes the approach and implementation of the Production Planning Consultant system (PPC). PPC is an expert system designed to support production planning for a semiconductor device line. Its purpose is not to generate an initial plan, but to deal with modifications to the plan. The planner's revision process consists of three subtasks; PPC supports each subtask by providing a bidirectional update propagation mechanism, a monitoring mechanism, and an inference engine. One of the characteristics of PPC is that it cooperates with the planner in revising a plan to make it satisfactory. An example of PPC execution is provided.<>