The BPMN model of a process represents an organized series of steps. At simulation, tokens traverse a sequence flow, respecting specified time constraints. They therefore simulate the time required for execution of a step before passing to the next step.

For an organizational process, the steps correspond to operations, events and gateways encountered during progress.

When a process is itself described by a diagram, or if an elementary tasks calls a process, the simulation editor hierarchically integrates the diagram associated with the process called. In this way the tokens move into the most detailed description levels of all the steps encountered.

It is also possible to consider a process described by a diagram as a simple processing step.

Participants and resources are objects that have an impact on process performance. Execution of a step can be delayed by unavailability of a required resource.