Stochastic Petri Nets: An Introduction to the Theory

Any developer of discrete event systems knows that the most impor tant quality of the final system is that it be functionally correct by exhibiting certain functional, or qualitative properties decided upon as being important. Once assured that the system behaves correctly, it is also important that it is efficient in that its running cost is min imal or that it executes in optimum time or whatever performance measure is chosen. While functional correctness is taken for granted, the latter quantitative properties will often decide the success, or oth erwise, of the system. Ideally the developer must be able to specify, design and implement his system and test it for both functional correctness and performance using only one formalism. No such formalism exists as yet. In recent years the graphical version of the Specification and Description Lan guage (SDL) has become very popular for the specification, design and partial implementation of discrete systems. The ability to test for functional correctness of systems specified in SDL is, however, lim ited to time consuming simulative executions of the specification and performance analysis is not possible. Petri nets, although graphical in format are somewhat tedious for specifying large complex systems but, on the other hand were developed exactly to test discrete, dis tributed systems for functional correctness. With a Petri net specifi cation one can test, e. g., for deadlock, liveness and boundedness of the specified system."