About this previous year paper
SOFTWARE QUALITY ENGINEERING (EIT061)
Section-wise Solved Answers & Notes
SECTION – A (10 × 2 = 20 Marks)
Very short & precise answers
(a) Types of software reviews
• Management review – progress & planning • Technical review – design & code correctness
• Inspection – formal defect detection • Walkthrough – author explains work to team
(b) Function points
Function Points measure software size based on functionality delivered to the user, independent of programming language.
(c) Hierarchical model of quality
It represents software quality in levels, where high-level quality factors are broken into criteria and metrics.
(d) Requirements of customer problem metrics
• Easy to understand • Customer-oriented
• Measurable • Relevant to quality goals
(e) Phase-based Defect Removal Pattern
It shows how defects are introduced and removed in different SDLC phases like requirement, design, coding, and testing.
(f) Fix quality vs Software quality
| Fix Quality | Software Quality |
|---|---|
| Quality of defect correction | Overall product quality |
| Short-term | Long-term |
| Local impact | Global impact |
(g) Backlog & Management Index
• Backlog: Pending defects yet to be fixed
• Management Index: Ratio of fixed defects to reported defects in a time period
(h) Software measurement
Software measurement is the process of assigning numbers or symbols to attributes of software for assessment and control.
(i) Statistical Software Quality Assurance (SSQA)
SSQA uses statistical techniques to monitor defects, failure rates, and process performance.
(j) Static & dynamic testing tools
• Static tools: Code analyzers, linters
• Dynamic tools: Test execution tools, performance testing tools
SECTION – B (Attempt Any Five) (5 × 10 = 50 Marks)
(a) McCall’s Quality Model
McCall’s model classifies quality into three perspectives:
Product Operation – correctness, reliability, efficiency, integrity, usability
Product Revision – maintainability, flexibility, testability
Product Transition – portability, reusability, interoperability
Example:
Reliability → failure frequency
Maintainability → mean time to repair
(b) Defect arrival & phase-based removal pattern
• Defects increase during coding phase • Most defects should be removed during early phases
• Late defect removal increases cost
Graph: Defect arrival vs time shows peak during testing.
(c) Software maintenance metrics • MTTR (Mean Time To Repair)
• Change request rate • Defect backlog
Example: Higher MTTR → poor maintainability
(d) Reliability growth model
Shows improvement of reliability over time as defects are removed.
Types: • Exponential model
• Logarithmic model • Delayed S-shaped model
(e) Why quality estimation is required?
• Predict product quality • Control cost & schedule
• Reduce risk
Quality estimation helps estimate project cost by predicting defect density and rework effort.
(f) Characteristics of modern testing tools
• Automation support • Regression testing
• Reporting & analytics • Integration with CI/CD
• Reusability
(g) SQE terms
(i) Mean Time To Failure (MTTF): Average operational time before failure.
(ii) Defect density:
Defect Density=Number of DefectsSize of Software\text{Defect Density} = \frac{\text{Number of Defects}}{\text{Size of Software}}Defect Density=Size of SoftwareNumber of Defects
(h) Quality planning & control
Quality planning: Defines quality goals, standards, and processes.
Quality control: Monitors results and takes corrective actions.
Example: Code reviews to control defect leakage.
SECTION – C (Attempt Any Two) (2 × 15 = 30 Marks)
Q3. Delayed S-Shaped Reliability Growth Model
This model assumes: • Slow defect detection initially
• Rapid defect removal in middle • Slow improvement at later stage
Graph: Failure rate vs time shows S-shape curve.
Use: Used when testing starts late or learning curve exists.
Q4. Short Notes
(i) Quality standards & processes
• ISO 9001 • CMMI
• Define procedures, audits, and documentation
(ii) Total Quality Management (TQM)
TQM focuses on continuous improvement, customer satisfaction, and involvement of all employees.
(iii) Major SQA activities
• Process definition • Audits & reviews
• Metrics collection • Testing support
• Documentation control
Q5.
(i) Software verification & validation
| Verification | Validation |
|---|---|
| Are we building it right? | Are we building right product? |
| Reviews | Testing |
| Process-focused | User-focused |
(ii) Static & dynamic testing tools
Static:
• Code review tools • Static analyzers
Dynamic:
• Unit testing tools • Performance testing tools
(iii) Proof of correctness
A mathematical technique used to prove that an algorithm or program satisfies its specification.