If you find that there are large portions in a workflow than can be factored out as an inclusion to simplify the original business use case, those parts can form a new business use case that is included in the original business use cases. Examples of such behavior are common behavior, optional behavior, and behavior that is to be developed in later iterations.

You should briefly describe every relationship you define.

See also Technique: Business Use-Case Model and Technique: Include-Relationship in the Business Use-Case Model.

If you find major parts of a workflow that form an option to the normal workflow, you can factor that part out to a new business use case that is an extension to the original business use case.

Make sure that the workflow of the original business use case is still complete and understandable in and of itself.

See also Technique: Business Use-Case Model and Technique: Extend-Relationship in the Business Use-Case Model.

In the business use-case model, use-case-generalizations can be used to find workflows that structure purpose and behavior.

See also Guideline: Business Use-Case Model and Guideline: Use-Case-Generalization in the Business Use-Case Model.

If two business actors interact with the same business use case in exactly the same way, they play the same role with respect to that business use case. To clarify this situation you can create a new business actor for this common role. The original business actors inherit this new business actor.

See also Work Product Guideline: Actor-Generalization in the Business Use-Case Model.

You should continuously evaluate the structure of your business use-case model to make sure it is understandable to your stakeholders.

See the checklists for business actor, business use case and business use-case model in Task: Review the Business Use-Case Model.