Introduction to Software Engineering 1

1. Introduction to Software Engineering
Muhammad Nasir
Software Testing Strategies
m.nasir@iiu.edu.pk

2. Agenda
 Software Testing
 What Software Testing Shows
 Strategic Approach
 Verification & Validation
 Who Test the Software
 Software Testing Strategy
 Strategic Testing Issues
 Unit Testing

3. Software Testing
“Software Testing is the process of
executing a software system with the
intent of finding errors prior to delivery
to the end user”

4. What Software Testing Shows

5. Strategic Approach

6. Verification & Validation

7. Who Test the Software?

8. Organizing for Software Testing
 Misconceptions regarding the use of
independent testing teams
 The developer should do no testing at all
 Testers are not involved with the project until it is
time for it to be tested
 The developer and Independent Test Group
(ITG) must work together throughout the
software project to ensure that thorough
tests will be conducted

9. Software Testing Strategy

10. Software Testing Strategy
 Unit Testing – makes heavy use of testing techniques that
exercise specific control paths to detect errors in each software
component individually
 Integration Testing – focuses on issues associated with
verification and program construction as components begin
interacting with one another
 Validation Testing – provides assurance that the software
validation criteria (established during requirements analysis)
meets all functional, behavioral, and performance
requirements
 System Testing – verifies that all system elements mesh
properly and that overall system function and performance
has been achieved

11. Strategic Testing Issues

12. Strategic Testing Issues

13. Unit Testing

14. Unit Testing

15. Unit Testing

16. Unit Testing
 Module interfaces are tested for proper
information flow.
 Local data are examined to ensure that
integrity is maintained.
 Boundary conditions are tested.
 Basis (independent) path are tested.
 All error handling paths should be tested.
 Drivers and/or stubs need to be developed
to test incomplete software.

17. The End
 Thanks for listening
 Questions would be appreciated.