Development of a computer simulator for dynamic scheduling of FMS to achieve optimal performance

This paper deals with the development of a simulation software using the features of visual interactive computer graphics for analysing the dynamic scheduling of a flexible manufacturing system (FMS) to cater to the need of fluctuating markets. While carrying out this work, the main concepts of dynamic modelling, computer simulation and visual interactive graphics have been used for studying the reduction in backlogs of workorders. In addition, queue length, waiting time and the capacity utilisation of the manufacturing system are also considered. The arrival pattern of components is fitted to a suitable distribution pattern based on the workorder position. The effects of despatching rules such as SPT, LPT, EDD, SIO, SLACK, SLACK/LRO on scheduling are analysed using the simulator to imitate the real life operation of FMS. Visual interactive computer graphics enables the user to find out machine utilisation levels, queue length of the components, throughput and comparison between the application of various despatching rules. Since dynamic queue records are maintained, it is possible to establish the various components waiting in the respective work centres and their attributes like lateness, slack, remaining operations etc. This software is very useful in enabling the user to select the appropriate despatching rule for the system. The software has been developed in the C language for IBM/PC compatible systems.