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BPMN models) into “equivalent” process models defined in an executable language,
such as YAWL. Accordingly, this chapter will discuss relationships between BPMN
and YAWL, and will show how BPMN models can be transformed to YAWL
nets.
The remainder of this chapter is organized as follows. Section 13.2 introduces the
Business Process Modeling Notation (BPMN). Section 13.3 explains the transfor-
mation from BPMN models to YAWL nets, and Sect. 13.4 presents the tool support
that was developed to automate the transformation.

13.2 BPMN

This section explains BPMN by example, distinguishing control-flow, data manip-
ulation, resource management, and exception handling aspects. The presentation of
BPMN is meant to be didactical rather than exhaustive.

13.2.1 Control-Flow

In BPMN, a process model is represented as a Business Process Diagram (BPD).
With reference to the running example of the book, Fig. 13.1 depicts a BPD corre-
sponding to a Freight In Transit process. This BPD consists of nodes of three types:
events (represented as circles), activities (represented as rectangles), and gateways
(represented as diamonds). Events denote things that happen at a particular point in
time, activities denote work that needs to be performed, and gateways serve to route
the flow of control along the branches of the BPD. Nodes are connected by means of
directed edges called sequence flows. A sequence flow basically says that the flow
of control can pass from the source node to the target node.

Freight in Transit
more Trackpoints
Issue Log Trackpoint
Trackpoint Order Entry
Notice

Create
Acceptance
Certificate
Freight delivered
Initiate
Shipment
Status Inquiry
24 hours

Fig. 13.1 Example of a business process model in BPMN