8.4Common Elements

The following sub clauses define BPMN elements that MAY be used in more than one type of diagram (e.g., Process,

Collaboration, and Choreography).

8.4.1Artifacts

BPMN provides modelers with the capability of showing additional information about a Process that is not directly related to the Sequence Flows or Message Flows of the Process.

At this point, BPMN provides three standard Artifacts: Associations, Groups, and Text Annotations. Additional Artifacts MAY be added to the BPMN International Standard in later versions. A modeler or modeling tool MAY extend a BPMN diagram and add new types of Artifacts to a Diagram. Any new Artifact MUST follow the Sequence Flow and Message Flow connection rules (listed below). Associations can be used to link

Artifacts to Flow Objects (see page 67).

Figure 8.8 shows the Artifacts class diagram. When an Artifact is defined it is contained within a Collaboration or a FlowElementsContainer (a Process or Choreography).

Figure 8.8 – Artifacts Metamodel

Common Artifact Definitions

The following sub clauses provide definitions that are common to all Artifacts.

Artifact Sequence Flow Connections

See “Sequence Flow Connections Rules” on page 40 for the entire set of objects and how they MAY be source or targets of a Sequence Flow.

An Artifact MUST NOT be a target for a Sequence Flow.

An Artifact MUST NOT be a source for a Sequence Flow.

Artifact Message Flow Connections

See “Message Flow Connection Rules” on page 41 for the entire set of objects and how they MAY be source or targets of a Message Flow.

An Artifact MUST NOT be a target for a Message Flow. An Artifact MUST NOT be a source for a Message Flow.

Association

An Association is used to associate information and Artifacts with Flow Objects. Text and graphical non-Flow Objects can be associated with the Flow Objects and Flow. An Association is also used to show the Activity used for compensation. More information about compensation can be found on page 300.

An Association is line that MUST be drawn with a dotted single line (see Figure 8.9).

The use of text, color, size, and lines for an Association MUST follow the rules defined in “Use of Text, Color, Size, and Lines in a Diagram” on page 39.

Figure 8.9 – An Association

Figure 8.10 – The Association Class Diagram

If there is a reason to put directionality on the Association then:

A line arrowhead MAY be added to the Association line (see Figure 8.11).

The directionality of the Association can be in one (1) direction or in both directions.

Figure 8.11 – A Directional Association

Note that directional Associations were used in BPMN 1.2 to show how Data Objects were inputs or outputs to Activities. In BPMN 2.0.2, a Data Association connector is used to show inputs and outputs (see page 220). A Data Association uses the same notation as a directed Association (as in Figure 8.11, above).

An Association is used to connect user-defined text (an Annotation) with a Flow Object (see Figure 8.12).

Announce

Issues for

Discussion

Allow 1 week for the discussion of the Issues — through e- mail or calls

Figure 8.12 – An Association of Text Annotation

The Association element inherits the attributes and model associations of BaseElement (see Table 8.5). Table 8.20 presents the additional attributes and model associations for an Association.

Table 8.20 – Association attributes and model associations

Group

The Group object is an Artifact that provides a visual mechanism to group elements of a diagram informally. The grouping is tied to the CategoryValue supporting element. That is, a Group is a visual depiction of a single CategoryValue. The graphical elements within the Group will be assigned the CategoryValue of the Group. (NOTE - CategoryValues can be highlighted through other mechanisms, such as color, as defined by a modeler or a modeling tool).

A Group is a rounded corner rectangle that MUST be drawn with a solid dashed line (as seen in Figure 8.13).

The use of text, color, size, and lines for a Group MUST follow the rules defined in “Use of Text, Color, Size, and Lines in a Diagram” on page 39.

Figure 8.13 – A Group Artifact

As an Artifact, a Group is not an Activity or any Flow Object, and, therefore, cannot connect to Sequence Flows or Message Flows. In addition, Groups are not constrained by restrictions of Pools and Lanes. This means that a Group can stretch across the boundaries of a Pool to surround Diagram elements (see Figure 8.14), often to identify Activities that exist within a distributed business-to-business transaction.

Figure 8.14 – A Group around Activities in different Pools

Groups are often used to highlight certain sub clauses of a Diagram without adding additional constraints for performance, as a Sub-Process would. The highlighted (grouped) sub clause of the Diagram can be separated for reporting and analysis purposes. Groups do not affect the flow of the Process.

Figure 8.15 shows the Group class diagram.