Knowledge capturing methodology in process planning

In process planning, a proper methodology for capturing knowledge is essential for constructing a knowledge base that can be maintained and shared. A knowledge base should not merely be a set of rules, but a framework of process planning that can be controlled and customized by rules. For the construction of a knowledge base, identifying the types of knowledge elements to be included is a prerequisite. To identify the knowledge elements, this paper employs a three-phase modeling methodology consisting of three sub-models: object model, functional model and dynamic model. By making use of the three-phase modeling methodology, four knowledge elements for process planning are derived: facts (from the object model), constraints (from the functional model), and way of thinking and rules (from the dynamic model). facts correspond to the involved data objects, and constraints to the technological constraints of process planning. The way of thinking is a logical procedure for quickly decreasing the solution space, and rules are key parameters to control the way of thinking. The proposed methodology is applied to the process planning of hole making. (C) 2003 Elsevier Ltd. All rights reserved.