A method and apparatus for creating a complex process model for use in a graphical environment, with the process utilizing defined entities including places, transitions, and arcs. Places represent data types, transitions represent actions, and arcs represent the connection of places and transitions. The places, transitions, and arcs may be interchanged by the user without the need to recreate the entire model. The invention also includes a method and apparatus of simulating a complex process, by identifying the attributes and values of the places and transitions, identifying the parameters of the connecting arcs, and manipulating the places, transitions, and arcs to constitute a process in action.