1. SEN 460 Software Quality Assurance

2. SEN 460 Software Quality Assurance
Bahria University Karachi Campus Waseem Akhtar Mufti B.E(CSE) UIT, M.S(S.E) AAU Denmark Assistant Professor Department of Computer Science Contact: Mobile: File access: tinyurl.com/sqa8cs

3. SEN 460 Software Quality Assurance
Text book Software Quality Assurance From theory to implementation By DANIEL GALIN

4. SEN 460 Software Quality Assurance
Chapter 3 Software Quality Factors

5. Incomplete quality requirements
Software quality drives specifications.
Quality depends upon specifications.
Correct specifications result into quality software.
Need for comprehensive software quality requirements.

6. Scenarios: Incomplete requirements
The new sales information system is correct but fails twice a day or often.
Reasons: incomplete requirements recorded. Or error in code or design.
RD-8.1 embedded software needs to be redesigned for a European version of the product. Although its previous version works properly.
Reason: Inflexible software design. Software design not capable to accommodate or change new functionality.

7. Quality Factors
For comprehensive definition of requirements the software requirement documents are classified into groups called “quality factors”.
McCall’s factor model.
Product operation factors.
Correctness, Reliability, Efficiency, Integrity, Usability.
Product revision factors.
Maintainability, Flexibility, Testability.
Product transition factors.
Portability, Reusability, Interoperability.

8. Quality Factors: Product operation factors.
Correctness
Correctness of a software is determined by the recorded list of outputs or behaviors.
Example: (1) sales invoice printout. (2) red alarms when temperature rises above 250 F.
Reliability
Deals with failures to provide service.
Determines the maximum allowed software system failure rate.
Refers to a component or entire system failure.

9. Quality Factors Efficiency
How much is the maximum throughput of a program.
The accomplished tasks per time unit by a software performed given in its minimum number of required environment values.
example:
The maximum efficiency of a cpu system program software achieved if given the minimum hardware platform values.

10. Quality Factors Integrity Usability
Deals with software system security.
To prevent access from unauthorized user.
Usability
Scope of staff needed to train new employee to operate the software system.

11. Quality Factors: Product revision factors.
Maintainability
Maintainability requirements determine the efforts to correct the software failures, addition or deletion of components.
Maintenance of software structure, program documents and user manuals.
Also includes the cases when a fixed number of classes are required per package. (a company coding standards).
Or a module will not exceed to its fixed number of lines of code.

12. Quality Factors: Product revision factors.
Flexibility
Resources required to adapt a software package to a variety of customers of the same trade, various extent of activities and different ranges of product.
Example:
A generic academic software is suitable by universities, schools, colleges or any type of academic institutes.

13. Quality Factors: Product revision factors.
Testability
Testability requirements for the ease of testing.
Special features in the program that helps the tester by providing predefined intermediate results and log files.
Automatic diagnostics performed by the software system prior to starting the system.
To find out if all the components of a system are in working order.
To obtain a report for detected faults.

14. Quality Factors: Product transition factors.
Portability
Portability requires the adaption of software system to other platforms.
Enables a software system to continue on different platforms simultaneously.
Reusability
?? Discussions.. (OOP concepts)
Give examples of your Final year project.

15. Alternative models of software quality factors
Verifiability.
Expendability.
Safety.
Manageability.
Survivability.