Plan and BPMN Modeling Elements

The Plan and BPMN-based processes use a similar set of modeling element in their workflows with some additional modeling element available for the BPMN-based process workflows so that you can model logic that is accommodated by Goal hierarchies:

• In a Plan, the workflow is triggered by the Plan.
• In a BPMN-Process, the workflow is triggered by the Process.

Plan Model

A Plan Model is a sum of all elements with execution semantics encapsulated in a Plan.

Every Plan Model:

• must contain one None Start Event, which is triggered, when the parent Plan becomes Running;
• must contain at least one End Event or an Activity with no outgoing flow;

Apart form that, it can contain an arbitrary number of activities, events, flows, and gateways connected with Sequence Flows (Connectors). The elements in the flows must meet their modeling rules and must create an uninterrupted workflow.

A Plan Model is triggered when the parent Plan becomes Running and its None Start Event produces a token and the respective namespace context is initiated.

BPMN Model

A BPMN Process Model is a sum of all elements with execution semantics encapsulated within a BPMN-based Process.

A BPMN-based Process:

• must contain at least one Start Event (it may contain several Start Events);
• must contain at least one End Events or an Activity with no outgoing flow;

Apart form that, it can contain an arbitrary number of activities, events, and gateways connected with sequence flows. The elements in the flows must create an uninterrupted workflow and meet any other modeling rules that apply.

Instantiation of Plans and BPMN Processes

When a Process with a None Start Event is instantiated:

1. Process namespace is created.
2. Local process context is initialized.
3. Process instance becomes Running and one Start Event produces token).
4. If there are no activity in the workflow (no more tokens in workflows), the Process instance is terminated and becomes Finished.

When a Process with another type of Start Event is instantiated:

1. Process namespace is created.
2. The respective Start Event condition is checked.
3. If the Start Event conditions are fulfilled, the local process contexts are initialized.
4. The Start Event triggers execution (releases the token) and the process instances becomes Running.
5. If there is no more activity in the workflow (no more tokens in workflows), the Process instance is terminated and becomes Finished.

Note: If a BPMN-based Process instance ends with an uncaught Error End Event, the last transaction is rolled back.

Events Flows Activities Gateway Swimlanes