Building a use case

A use case consists of one or more flows, which are built using a sequence of use case steps. Every use case has a main flow that generally describes the main, or default, path through the use case.

Blueprint allows you to add alternate flows to your use cases. Alternate flows begin after a decision point, where the use case splits into two or more directions. An external alternate flow is the same as an internal alternate flow, except the flow is contained in a separate use case artifact.

Use case steps are typically associated with an actor, and are sometimes associated with UI mockups and other use cases. Actors are associated with use cases to clearly demonstrate the person or system that performs that task. Associating UI mockups with use case steps enhances the simulation experience, providing viewers with a richer and clearer understanding of the use case. Including a use case in a step can be beneficial when a step is high level and you want to link the step to another use case that demonstrates the lower level steps that are required to complete that particular step. It also provides a way to reuse common functions across multiple use cases.

Key Terms and Concepts

• A use case describes an interaction between an actor and the system that yields an “observable result of value” to the actor.

• An actor can be any person, role, organization, application, system, and so on, that interacts with the system being modeled.

• A pre condition lists the state(s) that must be true before the use case can begin.

• A post condition lists the state(s) that will always be true at the completion of the use case, regardless of the path or scenario followed.

• A use case step describes a discrete action performed by an actor or by the system being modeled.

• A main flow describes the typical set of steps that should occur in order to satisfy the post conditions of the use case.

• An alternate flow describes an optional series of steps that satisfies the post conditions of the use case.

• An internal alternate flow is an alternate flow defined within a use case.

• An external alternate flow is an alternate flow that is included from an separate use case.

• A UI Mockup is a prototype of a user interface in the system. UI mockups are effective on a standalone basis, but are even more powerful when they are viewed in simulations.

Typical use case creation

Use cases are typically created as follows:

1. Define the pre condition and the post condition.
2. Add new use case steps to define the main flow.
3. Set actors on the use case steps.
4. Include use cases in the use case steps, if applicable.
5. Add alternate flows, if applicable
6. Add UI mockups to the use case steps, to enhance the simulation experience.

Use Case Example

The following example shows a use case in split view, which includes both the text view and the workflow view in the main content area at one time.

Tasks

Adding use case steps

Merging use case steps

Deleting use case steps

Adding an internal alternate flow

Adding an external alternate flow

Changing an external use case

Setting start and return steps

Adding an actor to a use case step

Including a use case in a step

Setting UI mockups on use case steps

Removing a UI mockup from a use case step

Rearranging the order of use case steps and flows

Learn More

Use cases

About the use case editor layout

Adding a use case

Deleting a use case

Blueprint Documentation|Blueprint eLearning|About Blueprint ©2015 Blueprint Software Systems Inc. All rights reserved Last updated: 10/7/2015