Anytime Assembly Sequence Planning

This paper describes an anytime optimization approach for assembly sequence planning. The well-known AND/OR-graph is applied to represent feasible assembly sequences. An optimal sequence is searched on the basis of this graph. Depending on multiple cost functions for each assembly step the first found plan might not be cost-optimal. Therefore the anytime approach allows finding the global cost-optimal sequence if the complete graph can be continuously parsed. In addition the returned solution can be re-evaluated at a later time allowing further optimizations in the case of changing production environments. The approach has been evaluated with different CAD-models each with varying graph sizes and assembly step costs.