THE ROLE OF QUEUEING NETWORKS IN MODELLING FLEXIBLE MANUFACTURING SYSTEMS

Queueing network models (QNM) have been used increasingly for modelling Flexible Manufacturing Systems (FMS). The capabilities of existing models are discussed, with reference to the different stages of a FMS project, from early design to system planning and scheduling. Particular attention is paid to QNM which can be used in the initial stage of system design where these models have proved to be a suitable and efficient tool for quickly feeding back aggregate information to designers. The need for enhancing QNM to cater for more realistic configurational and operational features is discussed. In particular, the issue of blocking, ignored by most models because of modelling difficulty, is emphasised, as the impact of blocking on performance can be substantial. Recent work by the present authors aimed at modelling blocking phenomena of two types of Material Handling System (MHS), namely, conveyer, and cart-type transporters is discussed.