Abstract:

The performance equivalence formulas of stochastic Petri nets can not be applied to analyze the time performance relative to instance arrival rate. To address the issue, the Petri net model was extended. The authors provided a new method of workflow modeling, i.eETdPN (Extended Timed Petri Net). Formal definition of extended timed Petri net was presented. Thereafter, this new method can be used to analyze four basic workflow models, i.e the sequence, parallel, choice and iteration model. We also provided a new calculation method of workflow response time by using queuing theory and stochastic Petri nets theory.  Finally examples of the four basic workflow models were evaluated with the proposed method using Exspect. Simulation results show that the largest relative error is about 2%, which proves the validity of the proposed method.

Key words: workflow model, timed Petri net, time performance analysis