ANSWER

BPMN is a robust notation designed to balance two competing needs.  The notation should be simple enough for all stakeholders to understand, yet robust enough to handle complex orchestration of events to a level of detail which can be made executable.  Not an easy thing to do.  However, by organizing elements into distinct categories, a sizable notation can be more easily understood.

BPMN organizes elements into 5 basic categories:

1. Flow Objects
2. Data
3. Connecting Objects
4. Swimlanes
5. Artifacts

Flow Objects are the main graphical elements which are used to define the behavior of a business process.  They are Activities, Events, and Gateways.

BPMN data is represented using 4 distinct elements types.  These are Data Objects, Data Inputs, Data Outputs, and Data Stores.

Connecting Objects connect Flow Objects together or to other information such as data.  They control the sequence of activities and the overall flow of the process. The types of connecting objects are Sequence Flows, Message Flows, and Associations.

Swimlanes are use to group primary modeling elements.  Swimlane is the category term used to represent Pools and Lanes.

Artifacts provide additional information about the process.  The two standard artifacts supported by BPMN are Groups and Text Annotation.  However, modelers and modeling tools are free to define their own additional artifacts.

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Chris Adams
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