A reliability analysis technique for object-oriented model using a reliability petri net

We propose a reliability analysis technique for the design specifications which are made by CRC methodology. We use a reliability Petri net as an analysis technique for CRC specification. The procedure of analyzing the system reliability is as follows: first, the collaboration graphs and message flow diagrams of CRC specification are transformed into an equivalent reliability Petri net which consists of places, transitions, input functions, output functions, failure rate of the input and output functions, and tokens. Secondly, we construct a reachability tree from a reliability Petri net, and establish the paths of all transitions for the reachability tree. These paths can be test cases. Finally, we calculate the values of reliability effect for all transitions in a reliability Petri net, select the transitions that have most effect on the system reliability, and search the messages and classes that are places of input and output fucntion in these transitions. Therefore, we can design these messages and classes very well for increasing the system reliability.