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Quality Metrics

Quality metrics provide essential insights into the health and effectiveness of our software development process. Here's why collecting and analyzing these metrics is crucial:

  • Early Detection of Issues
    • Helps identify and fix defects before they reach production
    • Reduces the cost of fixing defects
  • Data-Driven Decision Making
    • Provides objective data to support process improvements
    • Helps prioritize quality initiatives based on measurable impact
    • Enables tracking of improvement efforts over time
  • Team Performance Optimization
    • Identifies bottlenecks in development and testing processes
    • Highlights areas where additional training or resources may be needed
    • Helps set realistic quality goals and benchmarks
  • Business Value
    • Demonstrates ROI of quality initiatives to stakeholders
    • Helps predict and prevent potential production issues
    • Supports better resource allocation decisions
  • Continuous Improvement
    • Establishes baselines for measuring progress
    • Facilitates goal-setting and tracking
    • Provides feedback on the effectiveness of process changes
  • Risk Management
    • Helps assess the quality impact of new features or changes
    • Identifies high-risk areas requiring additional attention
    • Supports better release decisions

By consistently collecting and analyzing quality metrics, teams can make informed decisions, improve their processes, and deliver higher quality software more efficiently. However, it's important to remember that metrics should be used as tools for improvement, not as punitive measures or the sole measure of success.

List of Quality Metrics (Client Side)​

Engineering/Common Quality Metrics​

  • Total/Periodic number of open defects
    • Tracks the current defect backlog and workload.
    • Goal: Maintain a decreasing trend to ensure defects are being addressed efficiently.
  • Total/Periodic number of fixed defects
    • Measures the team's defect resolution rate.
    • Goal: Demonstrate consistent or improving resolution velocity.
  • Total/Periodic number of returned defects during manual checkup
    • Evaluates the effectiveness of initial fixes and quality of solutions.
    • Goal: Minimize returns by ensuring thorough fixes the first time.
  • Total/Periodic number of defects found in production
    • Assesses the effectiveness of pre-production testing.
    • Goal: Minimize production defects through improved testing and quality processes.
  • Total/Periodic number of defects found by customers/end users
    • Indicates gaps in internal testing processes.
    • Goal: Reduce customer-found defects by strengthening internal testing.
  • Number of defects found during each regression testing
    • Measures the stability of existing functionality.
    • Goal: Minimize regression defects by ensuring changes don't break existing features.
  • Defect Severity Index (DSI) = Sum of (Defects Count * Severity Level) / Total number of defects
    • Provides weighted measure of defect impact.
    • Goal: Maintain low DSI by prioritizing high-severity defects.
  • Customers/end users satisfaction score
    • Measures overall quality from user perspective.
    • Goal: Maintain high satisfaction scores through quality deliverables.
  • Test coverage
    • Indicates thoroughness of automated testing.
    • Goal: Maintain high coverage levels (typically 80%+) to ensure code reliability.

QA Metrics​

  • Average Time to Test a Bug Fix = Total time between bug fix & retest for all bugs / Total number of bugs
    • Measures efficiency of testing process for bug fixes.
    • Goal: Minimize testing time while maintaining quality of verification.
  • Cost per bug fix = Hours spent on a bug fix x developer’s hourly rate
    • Measures the cost efficiency of bug fixes.
    • Goal: Minimize costs while maintaining quality of verification.
  • Defect Category = Defects belonging to a particular category/ Total number of defects.
    • Helps identify patterns in defect types (e.g. UI, functionality, performance) to target process improvements and training needs.
    • Goal: Use category insights to implement preventive measures and reduce recurring defect types.
  • Defect Density = Defect Count/Size of the Release/Module
    • Measures the number of defects relative to the size of code changes, helping identify problematic modules or releases that need refactoring.
    • Goal: Maintain low defect density by improving code quality through better design, testing and reviews.
  • Defect injection rate = Number of tested changes / Problems attributable to the changes
    • Measures the rate of defects introduced by changes.
    • Goal: Minimize defects by improving testing processes and code quality.
  • Defect Leakage = (Total Number of Defects Found in UAT/ Total Number of Defects Found Before UAT) x 100
    • Indicates the proportion of defects that were not detected in earlier testing stages.
    • Goal: Minimize leakage by strengthening testing processes and improving defect detection.
  • Defect Removal Efficiency (DRE) = Number of defects resolved by the development team/ (Total number of defects at the moment of measurement)
    • Measures how effectively the team identifies and removes defects during development before they reach production.
    • Goal: Achieve high DRE (>95%) to minimize defects reaching customers and reduce overall maintenance costs.
  • Mean Time To Detect (MTTD) = Amount of time spent locating a defect / Total number of defects located
    • Measures average time taken to identify defects, indicating effectiveness of testing and monitoring processes.
    • Goal: Minimize MTTD to catch defects earlier in development cycle when they are less costly to fix.
  • Mean Time To Repair (MTTR) = Amount of time spent fixing a defect / Total number of defects located
    • Measures average time taken to fix defects once identified, indicating development team's efficiency.
    • Goal: Reduce MTTR to improve system reliability and user satisfaction.
  • Number of bugs per test = Total number of defects / Total number of tests
    • Indicates test suite effectiveness in finding defects and potential areas needing more test coverage.
    • Goal: Balance this ratio to ensure tests are meaningful and productive at finding issues.
  • Number of Test Runs Per Time Period = Number of test runs / Total time
    • Measures testing velocity and continuous integration efficiency.
    • Goal: Maintain high frequency of test runs while ensuring quality of execution.
  • Review Efficiency (RE) = Total number of review defects / (Total number of review defects + Total number of testing defects) x 100
  • Schedule variance (if testing finishes earlier than planned) = Planned schedule – Actual schedule
    • Measures how much ahead of schedule testing completed, indicating process efficiency.
    • Goal: Maintain positive variances while ensuring thorough testing.
  • Schedule variance (if testing finishes later than planned) = Actual schedule – Planned schedule
    • Measures delays in testing completion, highlighting potential process bottlenecks.
    • Goal: Minimize negative variances through better planning and execution.
  • Test Case Effectiveness = (Number of defects detected / Number of test cases run) x 100
    • Measures how good test cases are at finding defects.
    • Goal: Optimize test suite to maintain high defect detection rate with minimal redundancy.
  • Test Case Productivity = (Number of Test Cases / Time Spent for Test Case Preparation)
    • Measures efficiency in creating test cases.
    • Goal: Improve productivity while maintaining test case quality and coverage.
  • Test Coverage = (Total number of requirements mapped to test cases / Total number of requirements) x 100
    • Measures how completely requirements are tested.
    • Goal: Achieve comprehensive coverage (100%) of all requirements through test cases.
  • Test Design Efficiency = Number of tests designed / Total time
    • Measures speed and productivity of test creation process.
    • Goal: Optimize test design process while maintaining quality and coverage.
  • Test Execution Coverage = (Total number of executed test cases or scripts / Total number of test cases or scripts planned to be executed) x 100
    • Measures completeness of test execution against plan.
    • Goal: Achieve 100% execution of planned test cases in each testing cycle.
  • Total/Periodic number of user support requests
    • Tracks volume of user-reported issues and support needs.
    • Goal: Reduce support requests through improved product quality and user documentation.