Guarded transition systems: A new states/events formalism for reliability studies

Abstract

States/events formalisms, such as Markov graphs or Petri nets, are widely used in reliability engineering studies. They have proved to be a very powerful tool both from conceptual and practical viewpoints. This article introduces a new states/events formalism, the so-called guarded transition system. The guarded transition system generalizes both block diagrams and Petri nets. It also makes it possible to handle looped systems, which no existing formalism is able to handle smoothly. Its use is illustrated by means of examples and several important issues such as composition and graphical representations are discussed. It is shown that current assessment methods for Markov graphs and Petri nets can be improved to a guarded transition system without a significant change of complexity.