Comparative performance analysis of a flexible manufacturing system (FMS): a review-period-based control

The flexibility of a flexible manufacturing system (FMS) has provided it with the capability to become one of the most suitable manufacturing systems in the present manufacturing environment of customized and an increasing variety of products with shorter life cycles. Significant research has been made on flexibility from different points of views. The paper focuses on the study of flexibility in FMS from the view of a decision-and-information system. In modelling flexibility and other physical and operational parameters of an FMS, researchers have mostly assumed a decision-and-information system has the capability of real-time control. The literature reports qualitatively that real-time control may be difficult to achieve and justify economically. The paper presents a comparative study of an FMS operating under real-time control, review-period-based control and reactive control. It also focuses on the comparative performances of the key parameters such as routing flexibility and control strategies of an FMS operating under these different modes of a decision-and-information system. It contributes an approach using simulation under Taguchi's method to study the various factors contributing to FMS performance and identifies the critical parameters for improving performance. The result shows that review-period-based control can be effectively implemented in an FMS with a lower flexibility level. Smaller review-period size can perform comparable with real-time control. The decision-maker must ensure the FMS's capability of having real-time control, otherwise it may result in a reactive control that may considerably deteriorate the performance. The results under Taguchi's method indicate that the routing flexibility and control strategy should have maximum relative percentage contributions in the performance of an FMS, while the decision-and-information system should have the minimum. Increasing the relative percentage contribution of a decision-and-information system may deteriorate the performance of a given FMS.