ITGS-213: Software Engineering Quality Assurance

Introduction to Software Engineering - ITGS-213

• Course title: Introduction to Software Engineering
• Course code: ITGS-213
• Topic: Software Quality Assurance & Testing
• Academic year: 2020-2021

Software Quality Assurance & Testing

• Introduction: Software Quality Assurance (QA) is a crucial activity in software development; ensuring the quality and compliance with industry standards (ACM, IEEE, ISO).

• Quality Assurance QA Activities:

  • Defining quality requirements and verifying their accuracy.
  • Implementing reviews, inspections, and walkthroughs for code and documentation.
  • Testing to ensure the software meets specified requirements.

• Quality Attributes:

  • Reliability: The program's ability to perform its functions without errors. More reviews and testing generally lead to fewer errors.
  • Maintainability: The ease of identifying and fixing errors.
  • Security: Data security, including access controls and protection from external threats.
  • Expandability: The program's ability to be updated and upgraded.
  • Accuracy: Precision in the program's results, usually measured in errors per thousand.
  • Performance: Responsiveness and processing speed.
  • Usability: Ease of use for the end-user, which requires a user-friendly interface.
  • Reusability: Ability to reuse parts of the program in future projects.

• Software Standards:

  • Facilitating communication between developers and clients.
  • Preventing past errors from recurring.
  • Ensuring system continuation even if some team members leave.
  • Unifying techniques and tools used by developers in an organization.
  • Obtaining high-quality products.

• Types of Standards:

  • Development process standards (e.g., complete requirements before implementation).
  • Product standards (e.g., consistent documentation, code formatting).

• Types of Software Errors:

  • Requirements errors (incomplete or inaccurate user needs).
  • Design errors (failure to translate requirements into proper design specifications).
  • Implementation errors (e.g., calculation errors in a payroll system).

Testing

• Importance: Testing takes about 40% of the total development time, particularly in complex software.

• Testing Activities: Independent testing teams collaborate with developers to identify and solve defects before final release.

• Testing Levels:

  • Unit Testing: Testing individual components/modules.
  • Integration Testing: Testing interactions between modules.
  • System Testing: Testing the entire system (e.g., security, recovery, performance, including specific tests like security and recovery).
  • Acceptance Testing: User acceptance; confirming the system meets user needs.

• Testing Methods (White Box / Black Box):

  • White-box testing (Glass Box): Tests code internally to ensure all paths are covered.
    • Specific testing methods include examining the flow graph and using McCabe complexity metric, and analysis of code structure.
  • Black-box testing (Functional/Behavioral): Tests the program without looking at the internal code, focusing on input and output.
    • Focuses on functionality from the user's perspective.

Methods of Software Testing

• Alpha Testing: Developers and testing teams test the software in the development environment. This is testing before Beta.
• Beta Testing: Users test the software in real-world scenarios to identify remaining issues after Alpha testing, before release. Examples include testing functions, assessing performance (Response Time Test), and iteratively addressing issues.

Additional Information

• Quality Control (QC): Monitoring the product throughout its development, using various manual and automated tests to compare against established standards within a feedback loop. The goal is maximizing product quality and minimizing production costs.
• Software Quality Assurance Plan (SQA): Document outlining evaluation criteria for software, reviews, and accepted standards to guarantee quality.
• Testing Methods: Examples include Alpha testing, Beta testing, White-Box testing, and Black-Box testing. White-Box and Black-Box are specific internal (code) and external (user perspective) testing methods respectively. There are various types of testing like: Security, Recovery, User, and acceptance.
• Testing Costs: Early error detection in the development lifecycle significantly reduces overall testing costs (e.g., a comparison illustrated by detailed costs presented in the slides/notes: initial testing costs versus post-release fixes).
• Testing Examples: Testing use cases and scenarios are explicitly mentioned, showcasing practical applications.
• Documentation Reviews: The slides/notes highlight the necessity of review of various documents (requirements, design) within the software development cycle.
• Testing Tools and Techniques : White and Black Box testing examples and practical scenarios and methods were mentioned.