Increase in flexibility: productive or counterproductive? - A study on the physical and operating characteristics of a flexible manufacturing system

In time-based performances of a manufacturing system, flexibility has played a pivotal role. Significant research efforts have been made from defining the various types of flexibility in flexible manufacturing systems (FMS) to the performance measurement index of flexibility levels. This paper focuses on the physical and operating characteristics of alternative machines (available by the virtue of flexibility), which may not have been explicitly modelled with flexibility. The decision-maker needs to know how physical and operating characteristics such as processing time, machine setting time, tool changing time, transportation time, control strategies enforced, etc. may influence the changed level of flexibility in an FMS. Does an increase in flexibility have the expected benefits or not? If benefits are present, then up to what level of flexibility? Answers to these questions will provide an insight to the decision-maker to decide a gainful level of flexibility for a given physical and operating characteristics of an FMS. This paper contributes an approach to identify productive and counterproductive performance zones of an FMS at different flexibility levels while considering physical and operating characteristics. It also demonstrates the need of modelling explicitly the physical and operating characteristics of a system with flexibility, and it presents a simulation study of these parameters for a given FMS. The results show that expected gains from an increasing level of flexibility may not be present while considering physical and operating characteristics. Flexibility can be increased strategically up to a certain level with benefits when considering the physical and operating characteristic of the system. A further increase in flexibility level may be counterproductive.