# Frequently Asked Questions (FAQ)

- How does DPMN compare to BPMN?
- Does DPMN have a formal semantics?
- Can I use DPMN for creating a business process simulation with Arena, Simio, AnyLogic, etc.?
- Is there a DPMN modeling tool?

## 1 How does DPMN compare to BPMN?

BPMN process diagrams can be used for making conceptual process models (e.g., for documenting existing business processes)
and process automation models for specific business process automation platforms. However, BPMN is not expressive enough for
making platform-independent computationally complete *process design models*, e.g., for business process simulation.

For instance, DPMN supports all essential concepts needed for modeling and simulating resource-constrained activities (resource roles, resource constraints and resource pools), while BPMN only supports modeling resource roles, but not resource constraints and resource pools.

DPMN makes a distinction between *Resource-Dependent Activity Scheduling* (RDAS) arrows and *Event Scheduling* arrows, as shown in the DPMN Process Diagram to the right.

## 2 Does DPMN have a formal semantics?

Yes, the formal semantics of DPMN is based on the semantics of *Event Graphs* (Schruben 1983),
which was originally defined in terms of
integer programming. Wagner (2017) has proposed a more general semantics of Event Graphs where such a graph
is decomposed into a set of transition functions ("event rules") such that a transition system (or *Abstract State Machine*) semantics is obtained.
This semantics can be easily extended to *Object Event Graphs*. Finally, the semantics of DPMN-A models ("Activity Networks") is obtained by
reduction to Object Event Graphs using two rewriting patterns, and the semantics of DPMN-PN models ("Processing Networks") is obtained by reduction to DPMN-A.

It has been an unfortunate course of the history of science that Event Graphs have not become more well-known and, instead of Event Graphs, Petri Nets have been chosen as the standard semantics of BP models, despite the fact that Event Graphs would have been a much more natural choice.

## 3 Can I use DPMN for creating a business process simulation with Arena, Simio, AnyLogic, etc.?

Yes, DPMN is an open (non-proprietary) Discrete Event Simulation (DES) modeling language for making platform-independent simulation design models, which can be implemented with any particular DES platform, such as Arena, Simio, AnyLogic, etc.

## 4 Is there a DPMN modeling tool?

At present, there is not yet a DPMN-specific modeling tool. You have to use a diagram drawing tool that supports the basic BPMN modeling elements and allows to draw the new DPMN modeling elements, such as Microsoft Visio or draw.io.