A Model for Performance Evaluation of Gracefully Degrading Systems

The paper provides a systematic approach to modelling and assessing gracefully degrading systems, exploiting the formalism offered by Petri Nets. The procedure followed is based on the definition of some fundamental modules, the composition of which allows a complete model of the system to be obtained. The model can then be solved by computer simulation or analytically by means of a class of Petri Nets to obtain interesting performance parameters. The paper examines a number of real cases and describes the results obtained