Simulation modelling of flexible manufacturing systems using activity cyclic diagrams

Flexible manufacturing systems represent an advanced class of automated manufacturing systems. Because of the complexity and dynamic behaviour of such systems, simulation modelling is becoming a popular method of facilitating FMS design and determining operational strategies. This paper illustrates the use of activity cycle diagrams as a graphical method for developing simulation models for two existing flexible manufacturing systems. A description of this graphical method is given, and some simulation models are presented. Various versions of the models were developed for each configuration because of the different production processes performed in the system. The influence of two different software packages (SIMFACTORY II.5 and VS7), which were used for the development of computer models based on activity cycle diagram conceptual models, is illustrated. Different models were developed for the same configurations and process plans, to allow for the level of detail that can be modelled by each software package. The conclusions discuss to what extent activity cycle diagrams are suitable for the development of conceptual FMS simulation models.