关键词: 工艺设计, 事例推理, 对象模型, 事例表达

Abstract: This paper presents an extended object model for case-based reasoning in process planning. The model can support the all process of case-based reasoning in process planning such as case representation， indexing，retrieving and case revise. It is different from traditional object model .The model extends traditional object-oriented model by including the relationship class used in express the relation between the cases ， constraints used in the manufacturing knowledge representation， index class used in case retrieving， solution class used in case revise. So a complex case can be represented using this model.

Key words: process planning, case-based reasoning, object-oriented model