Modeling and implementing of a flexible workflow system which supporting engineering change

To improve the flexibility of workflow systems, efforts need to make both in flow modeling and system designing. An extended time interval Petri net by adding a fired mark on every transitions is used in workflow modeling, which satisfy parallel, concurrent and feedback demands of workflow; then a workflow model for complex and changeful flow is discussed on the background of engineering changes (ECs). Some strategies used in improving flexibility of workflow system are present and demonstrated by a prototype system too.