1. Team Skill 6 - Building The Right System Part 1: Applying Use Cases (Chapters 25-26 of the requirements text) CSSE 371 Software Requirements and Specification Don Bagert, Rose-Hulman Institute of Technology October 3, 2005 Thanks to Steve Chenoweth for some of the slides included.

2. 2 Outline Use Cases in Design and Implementation From Use Cases to Test Cases

3. 3 Use Cases in Design and Implementation

4. 4 What Are the Design Issues? Sometimes it is easier to design and implement a system feature than others For instance, if a feature mostly involves interaction between the software and one or more actors, the use case events correspond well with the steps of the implementation algorithm

5. 5 What Are the Design Issues? (continued) However, in other cases, such as when quality requirements or complex data structures are involved, the design does not follow as directly When the form of the requirements and the form of the design and implementation are different, we say that their correlation is orthogonal.  You have to stir in use cases and those quality attribute scenarios!

6. 6 Solving the Orthogonality Problem A potential solution: comes from the software architecture The software architecture helps us understand what the system does and how it works, how the elements interact, and what type of patterns and pieces or the system are involved

7. 7 Solving the Orthogonality Problem (continued) Architectural views : –Logical (for users) –Implementation (programmers) –Process (integrators) –Deployment (system engineers) –Use-case view (designers/testers; ties things together) Adding design details to a use case can also sometimes help - see http://www.rose-hulman.edu/class/csse/csse497/Process/detailed_use_case_model_template.html

8. 8 From Use Cases to Test Cases

9. 9 Acceptance Test Cases Acceptance (or validation) test cases are ones that are performed from the user’s point-of-view. –They are examples of black-box test cases (i.e. no knowledge of internal working of the software) Use cases are not exactly validation test cases, although use cases do drive the process of validation test case generator Steps in creating a test case: –Identify use-case scenarios (basic and alternate flows) –Identify the test cases –Identify the test conditions –Add data values to the test case

10. 10 Test Case Description Table For a Use Case Test Case Id ScenarioDescriptionCond. 1 Cond. 2 Cond. 3 Expected Result Actual Result Use as many conditions as necessary for a use case,

11. 11 Test Plans 1.There’s a “test plan” for how to do all these test cases. 2.The use cases each become multiple test cases in the test plan.