Test Estimation Lecture Notes

Overview

Test estimation is a crucial part of testing, often viewed as a sub-project within the larger project. Test estimation helps determine the time and effort required for various testing tasks and cycles.

Work Breakdown Structure (WBS)

• Begin with a Work Breakdown Structure (WBS) that outlines:
  • Stages
  • Activities
  • Tasks and Subtasks
• Identify phases of the testing cycle:
  • Planning and Control
  • Analysis and Design
  • Implementation and Execution
  • Evaluating Exit Criteria and Reporting
  • Test Closure Activity
• Break down activities and tasks within each phase.
• Estimate the time required for tasks and subtasks to complete the testing cycle.

Estimation Techniques

Consultative Approach

• Input from experts and individual contributors such as technology experts, business experts, and testers.
• Prepare the WBS collaboratively.
• Team discusses effort, duration, dependencies, and resource requirements.
• Bottom-up approach: Starts at the task/subtask level and sums up to higher levels.
• Used when previous project metrics are unavailable.
• Disadvantage: Relies on individual estimations.

Matrix-Based Approach

• Uses metrics from past, similar projects for estimation.
• Includes:
  • Developer-to-tester ratios
  • Project size and complexity comparison
  • Average time to execute test cases
• Mathematical Models: Use past data to estimate current project efforts. Considers factors like the number of test cases, defects, and time taken for execution and retesting.
• Advantage: More reliable; based on historical data.

Factors Affecting Test Effort

Product Factors

• Documentation: Poor or insufficient documentation increases test effort.
• Complexity: More complex projects require more effort.
• Size: Larger projects require more effort.

Process Factors

• Availability of Tools: Availability reduces manual effort.
• Development and Test Environment: Ready environments reduce setup time.
• Process Maturity: Mature processes reduce overall effort.

People Factors

• Team Skills: Skill availability (e.g., automation) affects effort. More skilled teams require less effort.
• Team Relationships: Good relationships can enhance productivity.

Time Factors

• Overall time constraints and deadlines can affect the required test effort.

Test Results Factors

• Number of defects found: More defects increase retesting and fixing effort.
• Retesting failures: Frequent failures in retests lead to more effort.
• Requirement changes: Changes and rework add to test effort.

Conclusion

Proper test estimation involves structured planning and understanding both the project and team capabilities. Choose the appropriate estimation technique (Consultative or Matrix-Based) based on data availability and project characteristics. Be mindful of the various factors affecting test efforts and plan efficiently to manage resources and timelines.