Part input into a flexible flow system: An evaluation of look-ahead simulation and a fuzzy rule base

This article reports an investigation into part-input methods for an implemented flexible flow system (FFS). Two new dynamic methods-look-ahead simulation and a fuzzy heuristic rule base-are compared to three simple myoptic static sequencing rules and one dynamic rule. It is shown using simulation that for the existing system, the best sequence generated from the minimum production set performs very well, but the dynamic methods outperform the sequence when the system is modified and the sequence is unaltered. It is concluded that for a stable FFS, the static determination of the best input sequence is appropriate, but that a rapidly changing FFS-due to machine breakdown, changes in production requirements, etc.-may benefit from a dynamic part-input method. The look-ahead simulation outperforms the fuzzy rule base, and appears to be a more promising dynamic method. Suggestions for future research and evaluation are given.