Unit 3: Software quality assurance
Managing Software Projects notes · PTU syllabus (MBA 943-18)
On this page
Unit summary
Quality must be built into software through reviews, standards and controlled change. This unit covers quality concepts and software quality assurance, formal technical reviews, software reliability, quality standards — ISO 9000, CMM and Six Sigma — the SQA plan, software configuration management activities and the project management plan.
After this unit you can
- Explain software quality concepts and SQA activities
- Conduct formal technical reviews
- Explain software reliability and quality standards
- Explain the SQA plan, SCM and the project management plan
PTU syllabus topics
- Quality concepts and SQA
- formal technical reviews
- software reliability
- quality standards (ISO 9000, CMM, Six Sigma)
- SQA plan
- SCM activities and project management plan
- 5 Optimising
Continuous improvement
- 4 Managed
Quantitatively controlled
- 3 Defined
Standard organisational process
- 2 Repeatable
Basic project management
- 1 Initial
Ad hoc
Topic 1
Quality concepts and software quality assurance
- Software quality: conformance to explicitly stated functional and performance requirements, documented development standards and implicit characteristics expected of professionally developed software.
Functional suitability
Performance efficiency
Compatibility
Usability
Reliability
Security
Maintainability
Portability
- SQA: planned and systematic activities to ensure software processes and products conform to requirements, standards and procedures — reviews, audits, testing strategy, measurement, defect tracking.
- Cost of quality: prevention, appraisal, internal failure and external failure costs — defects cost far more to fix after release.
Topic 2
Formal technical reviews
- FTR: a meeting of 3–5 people (producer, review leader, reviewers, recorder) to uncover errors in a work product — requirements, design or code.
- Guidelines: review the product not the producer, set an agenda and keep to it, limit debate, find problems rather than solve them, take written notes, use checklists, keep meetings under two hours.
- Forms: walkthroughs, inspections (Fagan), peer code reviews, pull-request reviews.
Topic 3
Software reliability
MTBF
Mean time to failure + mean time to repair
Availability
MTTF ÷ (MTTF + MTTR) × 100
Failure intensity
Failures per unit of execution time
Example
MTTF 980 hours and MTTR 20 hours: availability = 980 ÷ 1,000 = 98%.
- Software safety: identifying and assessing hazards that could cause harm (medical, aviation, automotive software).
Topic 4
Quality standards
ISO 9001 (with ISO/IEC 90003 guidance)
Quality management system
Documented processes, audits, continual improvement
CMM / CMMI
Process maturity
Five levels — initial, managed (repeatable), defined, quantitatively managed, optimising
Six Sigma
Reducing variation and defects
DMAIC for existing processes; DMADV for new ones; 3.4 defects per million opportunities
- Many Indian IT firms achieved CMMI Level 5 — a factor in global outsourcing contracts.
Topic 5
The SQA plan
- Contents (IEEE 730): purpose and scope, reference documents, management (organisation, tasks, responsibilities), documentation, standards and metrics, reviews and audits, testing, problem reporting and corrective action, tools and methods, supplier control, records, training, risk management.
Topic 6
Software configuration management
- 1Identification
Name and version configuration items
- 2Version control
Track versions (Git)
- 3Change control
Change requests, impact analysis, change control board approval
- 4Configuration audit
Verify changes were made correctly
- 5Status reporting
Who changed what, when
- Baseline: a reviewed and approved work product that can be changed only through formal change control.
Topic 7
The software project management plan
- Contents (IEEE 1058): overview, project organisation, managerial process (estimates, schedule, resources, risk, monitoring), technical process (methods, tools), supporting processes (SCM, SQA, verification), work packages, schedule and budget.
Key terms
- SQA
- Systematic activities assuring software quality
- Formal technical review
- Structured meeting to find errors in work products
- MTBF
- Mean time between failures
- CMMI
- Capability maturity model integration
- Baseline
- Approved work product changed only through formal control
Quick revision
- Quality definition; ISO 25010; SQA; cost of quality.
- FTR roles and guidelines; inspections.
- MTTF, MTTR, MTBF, availability; safety.
- ISO 9001, CMMI levels, Six Sigma.
- SQA plan (IEEE 730); SCM activities; SPMP (IEEE 1058).
Important exam questions
Practice questions written to the PTU exam pattern for this unit's syllabus: short answers (Section A style) and long answers (Sections B and C style).
Short-answer questions
- Q1.Define software quality.
- Q2.State four guidelines for formal technical reviews.
- Q3.How is availability calculated?
- Q4.Name the five levels of CMMI.
- Q5.What is a baseline in SCM?
- Q6.List the SCM activities.
Long-answer questions
- Q1.Explain software quality concepts and SQA activities.
- Q2.Explain formal technical reviews and software reliability measures.
- Q3.Compare ISO 9000, CMMI and Six Sigma for software quality.
- Q4.Explain the SQA plan, software configuration management and the project management plan.
Stuck on this unit?
Message SBS on WhatsApp for help with Managing Software Projects, or to ask about studying MBA at Synetic.