Construction and performance analysis of a Petri net model based on a functional model in a CIM system

Abstract

The so-called functional models, such as IDEF0, are useful tools for describing, designing and analysing the functional aspects of a complex manufacturing system, for example a CIM (computer integrated manufacturing) System. Though it involves considerable time and cost to build a sound functional model, the model usually cannot be used directly in further systems analysis procedures, such as quantitative performance analyses, due to its informal nature. To overcome this problem, we suggest a Petri net based procedure. First, we build a Petri net model from the IDEF0 and IDEF3 models, both of which are functional modelling tools widely used in real applications. Then, employing steady-state analysis for the Petri net, we propose a method to obtain performance measures such as the production rate. Since the analytical ability of a Petri net diminishes with increasing manufacturing system size, we develop a technique to aggregate and consolidate the Petri net to alleviate this problem that is associated with increasing complexity. An example problem is included to show the viability of our method for constructing a Petri net from a functional model and to evaluate the performance of the Petri net in an analytic manner.

An upper bound on the cycle time of a stochastic marked graph using incomplete information on the transition firing time distributions

“…Stochastic marked graphs have been used to model ratio-driven manufacturing systems [13] and in cyclic flow lines where identical sets of jobs are repeatedly produced in the same loading and processing sequence [8]. Links have been made between functional models like the IDEF families and Petri nets to model more complex manufacturing systems [6,7]. As long as these models fit into the stochastic marked graph framework the above bounds may help in evaluating uncertainties in performance.…”