Mapping business process diagrams to UML use case diagrams
You can transform a Business Process Modeling Notation (BPMN) business process diagram to a Unified Modeling Language (UML) use case diagram. In this manner the BPMN business process diagram and UML use cases are integrated and traceable. Specific tasks on business process diagrams are linked to use cases, which in turn are linked to the functional software components that perform them. As the software develops and matures, the business justification for each software element and feature can be derived from or traced back to the Business Process Model.
On a BPMN business process diagram, you model processes in a hierarchical fashion. At the highest level within a process flow you model processes, and then create one or more child diagrams for each process to show finer-grain process flow details. On the child diagrams, the processes that you model are considered subprocesses. Each subprocess can be decomposed further, to create multiple levels of nesting, to a potentially infinite level. When a subprocess cannot be decomposed further, it is considered a task. A task is therefore the lowest level of process that needs to be described from a business perspective.
This is different than use case modeling, which does not necessarily specify hierarchical decomposition of use cases. In order to facilitate the transformation of a business process diagram to a UML use case diagram, you must select each task, or lowest-level business process, that you want translated to a use case. You then specify an execution type for each task you want mapped to a use case.
1 Open an existing or create a new BPMN business process diagram.
The diagram must include one or more Processes.
2 For each process that you want to map to a UML use case, complete the following steps:
▪Open the BPMN Process definition dialog box by double-clicking the Process.
▪Click the Analysis tab, navigate to page 2, and then in the Use Case Support section, specify one of the following execution types:
Manual: Processes that do not have any system interaction.
Automatic: The whole process is an interaction with the system. For each process that defines process steps that you want mapped to use case steps, in Execution Type, select Automatic. Only process steps that are specified as being automatic are mapped to use case steps.
Automatic and Manual: The process is a mix of manual steps and system steps.
Only processes specified as Automatic or Automatic and Manual are mapped to use cases on a use case diagram. A process maps to a use case of the same name.
▪You can also specify process steps for a process, which map to use case steps of the generated use case. To specify process steps, complete the following steps:
On the Analysis tab, navigate to page 3; then type the steps in the Process Steps field.
To specify that a process step is automatically performed by the system, at the end of each process step, select the Automatic check box. Only process steps specified as Automatic are mapped to the corresponding Use Case Steps property in the generated use case diagram.
If you specify a Process Execution Type as Automatic, do not include nonautomatic steps in the Process Steps section. A Process that is Automatic and Manual can includes a set of process steps that are mixed.
▪Click OK.
3 Open the relevant Business Process (BPMN) to Role matrix and associate a business end user with the business process.
4 Click Dictionary > Export to Use Case Diagram.
5 Specify if the export is to be to an existing use case diagram or new one. If you want to export to a new diagram, specify its name and owning package.
6 To start the export operation, click OK.
Result
The Business Process to Use Case mapping generates the following results:
▪A new use case diagram is created, or an existing use case diagram is reused as specified.
▪For each lowest-level process that has an execution type set, a use case definition is created, as part of a package. The use case definition is created with the same name as the business process it is mapped from.
▪Use case symbols for each mapped use case definition are added to the diagram if not already present.
▪Process Steps that are marked Automatic are added to the use case definition as Use Case Steps.
▪If a Process is mapped to a Role in the Business Process to Role matrix, then it is added as a corresponding actor to the diagram if not already present, with the same name as the role.
▪A use case association is added between the actor and the use case, if not already present in the diagram. The association is derived from the Business Process To Role matrix.
Next
Now you can further elaborate and develop the use case diagram using UML modeling techniques.