Software maintenance is a time taking activity in the real world. Execution time of software maintenance process may get
increased due to interdepartmental communication, thus, increasing the cost and decreasing the performance of the
process. We suggested performance evaluation of software maintenance process through the transformation of activity
diagram into generalised stochastic Petri nets (GSPN). For this study, execution time and cost of maintenance process are
defined as performance measures, and the role-based approach is used to understand the flow of software maintenance
activities in a software organisation. Activity diagram is constructed to be transformed into GSPN. We used PIPE2 to analyse
the GSPN. PIPE2 calculates average number of tokens on a place in the GSPN, throughput of timed transition and state space
analysis. State space involves calculation of the reachability of the GSPN net that shows whether a GSPN holds the property
of safeness, boundness and is deadlock free.