This paper reports part of the results of a 3 year project carried out at Cranfield University in collaboration with companies in the automotive and aerospace industry, aiming to develop new methodologies for computer aided assembly process planning (CAAPP). CAAPP is not a mature technology, despite the managerial and technical advantages offered by its implementation. This paper describes the limiting factors in industrial acceptance of CAAPP and discusses methodologies by which these factors can be eliminated. This is done primarily by the integration of CAAPP functionality with a product data management (PDM) tool, providing a data control framework and a high-level data structure to form the basis of planning. The paper also details a system based on the described approach. The underlying object-oriented model developed to facilitate automated assembly process planning is described in detail. Data control methodologies are presented to aid retrieval, storage and creation. Methods for the definition of liaisons, mating features, are discussed. The methodologies used for constraint identification, process sequence generation and sequence representation within the system are described. Multiple sequences are represented by means of a tree structure, similar to the AND/OR graph representation. The sequence is navigable and can be used for downstream sequence evaluation and simulation or to generate scheduling data.
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