Definition of the model-"Stochastic timed well formed coloured nets"

A model able to deal with the main characteristics of the real-time distributed systems (complex systems with a big number of components; systems with a lot of different time characteristics and, in particular, time constraints) is defined. The stochastic timed well-formed colored nets (STWN model) are based on two underlying models: the well-formed colored nets (WN) which provide both a concise and a structured representation and are well adapted for representing big systems composed of sets of components with a common behavior, and the stochastic timed Petri nets (STPN model) which have the ability to deal with combinations of arbitrary distribution (exponential, deterministic (time 0 and /spl plusmn/ 0), uniform and mixed) and are well adapted for representing systems with time constraints (time critical systems). The analysis of the dynamic behavior of an STWN model is based on an object called the randomized symbolic state graph, which is an aggregated semi-Markov process which allows a lot of performance evaluations. Simple and illustrative examples showing the advantage of the STWN model are presented.<>