Assembly sequences planning for simultaneous engineering applications

This paper describes a Generative Assembly Process Planner (GAPP) used to generate and evaluate assembly sequence alternatives which can be used in simultaneous engineering applications. Given a graph model of the product to be assembled, optimal assembly sequences are automatically generated and evaluated in a single process. Geometric feasibility and accessibility constraints on assembly operations which help prune the search space are presented. Assembly-related criteria which guide the search to an optimal solution are described. These include: number of reorientations, concurrent execution of assembly tasks, grouping of similar tasks and stability criteria. The relative weights of various criteria can be varied interactively resulting in different optimal assembly sequences. The ability of GAPP to generate and evaluate assembly alternatives when various criteria are enabled or disabled or their relative importance is changed makes it an effective tool for simultaneous engineering/manufacturing applications. Examples are included to demonstrate GAPP's use and potential for assessing assembly, disassembly, repair and maintenance procedures.