Software Quality Metrics Product Quality Metrics MCA AKTU Notes
Software quality metrics are simple ways to measure how good a software product is. In easy words, they help us check whether software works well, has fewer mistakes, and satisfies users. Just like teachers use marks to judge student performance, software companies use quality metrics to judge software quality.
These metrics help developers find problems early, improve software step by step, and deliver better products to customers. For exams and jobs, understanding these metrics helps students think like software professionals.
Why this topic matters
Helps in building reliable software
Reduces future problems and costs
Improves user trust and satisfaction
Product Quality Metrics
Product quality metrics focus on the final software product that users use. These metrics tell us how many problems exist, how users feel about the software, and how useful the software is. Companies check these metrics after or near completion of the software.
Defect Density
Defect density means how many mistakes (defects) exist in software compared to its size. A defect is any error, bug, or fault in the software. If software has many defects in a small size, its quality is poor. If defects are few, quality is better. This metric helps companies compare two software products easily.
Real-life example
Think about a notebook. If 2 pages
have mistakes in a 100-page notebook, quality is good. If 20 pages have
mistakes, quality is bad.
Key points
Defect = mistake in software
Lower defect density = better quality
Used to compare software quality
Exam Tip 📝
Definition of defect density is very
important for exams.
Customer Problems Metric
Customer problems metric shows how many problems customers face after using the software. These problems include complaints, error reports, and support calls. This metric helps companies understand real user issues, not just internal testing results. Fewer customer problems mean better software quality.
Real-life example
If many users complain that a shopping
app crashes during payment, the app quality is poor.
Key points
Based on customer feedback
Includes complaints and support calls
Shows real-world software issues
Remember This 📌
Customer problems metric focuses on
after-release issues.
Customer Satisfaction Metrics
Customer satisfaction metrics measure how happy users are with the software. Companies usually collect this data using surveys, ratings, and reviews. High satisfaction means users like the software and find it useful. Low satisfaction means improvements are needed.
Real-life example
Google Play Store ratings show
customer satisfaction for mobile apps.
Key points
Based on surveys and ratings
Shows user happiness
Important for business growth
Exam Tip 📝
Always mention surveys and ratings in
answers.
Function Points
Function points measure what the software can do, not how big it is in code. It checks features like input, output, and user interaction. This metric helps estimate effort, cost, and quality. Even beginners can understand it as counting useful functions.
Real-life example
In a college app, login, attendance
view, and result download are function points.
Key points
Measures functionality
Independent of programming language
Helps in planning and estimation
In-Process Quality Metrics
In-process quality metrics measure quality while software is being developed. These metrics help teams find problems early and fix them before final release. Early detection saves time and money.
Defect Arrival Pattern
Defect arrival pattern shows when defects are found during development. If many defects appear early, the team can fix them easily. If defects appear late, fixing becomes costly. This pattern helps teams improve their work process.
Real-life example
Finding mistakes while writing notes
is easier than correcting them just before exams.
Key points
Shows timing of defect discovery
Early detection is better
Helps in process improvement
Phase-Based Defect Removal Pattern
This metric checks in which stage defects are removed. Stages include design, coding, and testing. Removing defects early is cheaper and safer. This metric helps teams identify weak development stages.
Real-life example
Correcting wrong syllabus selection
early avoids problems later.
Key points
Tracks defect removal stage
Early removal saves cost
Improves development process
Defect Removal Effectiveness
Defect removal effectiveness shows how well a team removes defects before release. High effectiveness means most defects are removed early. Low effectiveness means many defects reach users.
Real-life example
If teachers correct most mistakes
before final exams, students perform better.
Key points
Measures defect removal success
Higher value means better quality
Important for reliable software
Exam Tip 📝
Link this metric with testing quality in
answers.
Metrics for Software Maintenance
Maintenance metrics measure quality after software release. Software needs updates, bug fixes, and improvements. These metrics help manage maintenance work effectively.
Backlog Management Index
Backlog means pending work. Backlog management index shows how well a team handles pending bug fixes. If backlog reduces, maintenance quality is good. If backlog grows, problems exist.
Real-life example
Pending assignments show student
workload management.
Key points
Backlog = pending issues
Lower backlog is better
Shows maintenance efficiency
Fix Response Time
Fix response time measures how fast problems are fixed after reporting. Faster response improves user trust. Slow response frustrates users.
Real-life example
Fast customer care response improves
shopping app rating.
Key points
Measures fixing speed
Faster response is better
Improves customer satisfaction
Fix Quality
Fix quality checks whether fixes actually solve problems. Poor fixes create new issues. Good fixes solve problems permanently.
Real-life example
Repairing a phone properly avoids
repeated visits to service centre.
Key points
Measures quality of fixes
Avoids repeated defects
Important for long-term quality
Software Quality Indicators
Software quality indicators are overall signals of software health. They combine many metrics to show general quality level. Managers use these indicators for decision-making.
Real-life example
Overall grades show student
performance, not just one subject.
Key points
Show overall quality
Help management decisions
Based on multiple metrics
Possible Exam Questions
Short Answer
Define defect density.
What is customer satisfaction metric?
Explain fix response time.
Long Answer
Explain product quality metrics with examples.
Describe in-process quality metrics.
Discuss software maintenance metrics.
Detailed Summary
Software quality metrics help measure and improve software quality at different stages. Product quality metrics focus on the final software and user experience. In-process metrics help detect and fix defects during development. Maintenance metrics ensure software remains reliable after release. Together, these metrics help companies deliver high-quality software, reduce costs, and increase customer satisfaction. For students, understanding these metrics builds strong exam answers and practical software knowledge.
Key Takeaways 📌
Metrics measure software quality
Early defect detection saves time
Customer satisfaction is very important
Maintenance metrics ensure long-term quality
Final Exam Memory Tip 🧠
👉 Measure → Improve → Satisfy → Maintain
These notes are designed for easy learning, deep understanding, and exam success.