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Lesson 11Use case scenarios
ObjectiveIdentify Scenarios in Relation to Use Cases.

Identify Scenarios in Relation to Use Cases

Use cases identify a primary goal of the system. When an actor attempts to accomplish a goal using the system, there are usually decisions or rules that could change the outcome. There may also be exception conditions that affect the accomplishment of the goal.

Scenarios explained and how they are used a number of ways

The word "scenario" is used a number of ways.
In the context of UML use cases, scenarios have a very specific meaning. Be careful not to confuse the more general usage with the explicit definition used here.
Draw UML Activity Diagram

Finding test cases

This definition for a scenario should remind you of another concept, test cases. Finding test cases is one of the key benefits of the use case approach to modeling. We have just finished the first of many models, and already we have a complete set of tests for our system. These tests will be refined as we continue modeling, but the framework is established.
So how do we find these scenarios? Use pictures. It's difficult sometimes to read a narrative and follow every possible path.
One very simple and practical tool to use to find the scenarios visually is a flowchart:

Use Case Scenario Described

Identify Scenarios Course Project Exercise

Click the Exercise link below to identify scenarios in the course project.
Usecase Scenario - Exercise