Identifying and Explaining Infeasible Assembly Operations

This paper presents a knowledge-based method for identifying infeasible assembly operations in the context of assembly sequence planning. In addition the reasons for the infeasibility are identified and these can guide product designers towards the necessary design changes to make a preferred assembly sequence feasible, or guarantee that an assembly sequence includes a specific partial assembly state. This capability increases the usefulness of assembly sequence planners as concurrent engineering tools by contributing to a closer integration between product design and assembly sequence planning. In the identification of infeasible assembly operations the concept of minimal infeasible sets of connections is introduced and two issues are addressed: the knowledge-based generation of these minimal sets, and their suitability to form a basis for a concise explanation of the causes of assembly operation infeasibility. Two simple examples illustrate practical applications of the method.