Ant Organisation Ltd

Workflow

Concept: Workflow instance

Represents a running workflow

Each time a workflow is started, the workflow engine creates a new workflow instance from the workflow definition and a new case for the workflow instance to manipulate, and sets the instance's parameters. The workflow instance represents the full state of the running workflow as it is executed, and the final state of the workflow when it has finished or been aborted.

The workflow instance contains activity instances corresponding to the activity definitions of the workflow definition, and these are contained in thread instances and segment instances that mirror the structure of the workflow definition.

It also contains the running state of the workflow, including which activities are waiting for responses from the system, what responses have been received already, the instance's case document, and the parameters that the workflow instance was started with. The workflow instance is informed by the workflow engine as it starts activities and collects responses from external systems.

Each workflow instance also contains:

		Status, status of the workflow instance, can be started, completed, terminated, aborted and suspended;
		Creator, user who created the workflow;
		Time of next escalation, Date and time that the escalation workflow is called if this workflow is not finished.

The workflow instance is based upon the latest published version of the workflow definition at the time it is started, and bound to this version even if the workflow definition is later modified.