Modeling guidelines for gateways
Gateways of the XOR (data-based) type: For all outgoing connections of an XOR (data-based) gateway, the value
Expression must be set for the
Condition attribute, and a valid expression must be used for the
Condition expression attribute.
Sequence flow, especially after gateways:
For every XOR gateway of the
XOR (data-based) type, the
Default gateway attribute should be specified for exactly one outgoing sequence flow connection (
activates connection type). Under no circumstances must multiple outgoing connections be marked with this attribute.
For each XOR gateway of the
XOR (event-based) type there must be at least two outgoing sequence flow connections (
activates or
leads to type).
For all outgoing connections of an event-based XOR gateway, no value must be specified for the
Condition attribute. The
Condition expression attribute should not be specified.
The following target objects are permitted for outgoing sequence flow connections of an event-based XOR gateway:
Functions for which the
Receive task type was set.
Intermediate events whose
Event type attribute type has a value other than
Compensation or
Multiple.
If there is a function in the set of target objects, this set must not contain an event of the
Message type.
If a gateway of the
OR type has no or exactly one incoming sequence flow connection, there must be at least two outgoing sequence flow connections.
For all outgoing sequence flow connections of an OR gateway, the value
Expression must be set for the
Condition attribute, and a valid expression must be used for the
Condition expression attribute. The expression must unambiguously relate to the current gateway.
If an OR gateway has exactly one outgoing sequence flow connection, no value must be specified for the
Condition attribute of this connection.
If a gateway of the
Complex type has no or exactly one incoming sequence flow connection, there must be at least two outgoing sequence flow connections.
For all outgoing connections of a complex gateway, the value
None must be specified for the
Condition attribute, especially if there is only one outgoing connection.
If a complex gateway has multiple incoming sequence flow connections, a condition that references the sequence flow names and process properties (data) must be specified for the
Incoming condition attribute.
If a complex gateway has multiple outgoing sequence flow connections, a condition that references the sequence flow names and process properties (data) must be specified for the
Outgoing condition attribute.
If an AND gateway has no or exactly one incoming sequence flow connection, there must be at least two outgoing sequence flow connections.
For all outgoing sequence flow connections of an AND gateway, no value must be specified for the
Condition attribute.