1. Personal Software Process Team Software Process
CSC 3380
Lecture 08

2. Sources
Introduction to the Personal Software Process by Watts S. Humphery, pp ,
Introduction to the Team Software Process by Watts S. Humphery

3. Product Quality Can’t retrofit a product to improve quality
From the beginning we need:
Quality standards;
Process standards;
Quality assurance mechanisms, responsibilities
Defect elimination is the principal metric
Done by reviews, compilation, and testing
Each such filter passes on a %age of defects
Testing is most expensive and least effective

4. Product Quality continued
Problems with testing
Hard to trace back from symptom to defect
Defects interact to mask each other
Tests are often enormous - testing is “blind”, so we must test for every category of defect
You never know that a product is defect-free
Keep individual/organization estimated filter rates
Individual review may not exceed 70% effectiveness - prototyping helps eliminate rest, which often arise in requirements, specification, and design errors

5. Filtering yields of different methods
Individual Code review
70% to 80%
Group Code Inspection
50% to 70%
Compilation
50%
Unit Testing
40% to 50%
Integration Testing
45%
Requirements (System) Testing
Algorithm Testing 8%

6. Process Quality As quality improves, removal rates decrease
Defect removal strategy:
Individuals develop high quality modules
Team inspects all module interfaces and interactions
Team validates all requirements and their presence in code
Individual conducts very complete unit test
Team does comprehensive integration testing
QA does thorough system testing

7. Process Quality Build in as much quality as you want to buy
Quality failure costs – fixing defects
Quality appraisal costs – reviews and other filtering that doesn’t remove defects
Defect prevention costs – process analysis and improvement efforts
Failure costs ~ compile and test costs
Appraisal costs ~ reviews
Personal process metrics
Appraisal/failure > 2.0 (primary metric)
Review yield >= 70% (use own checklist)
When achieved, cull checklist and do prototyping

8. Major Insights of Introductory Team Software Process
Teams are the norm; they speed up development,bring skills/experience to bear
Teamwork is synergistic; this requires:
Training and experience
Common goals and good communication
Acceptance of assigned roles
Environmental support (management)
Accepted process, including planning
Commitment to all the above
Mutual respect and support
Teams are fun and satisfying as well as productive

9. The Team Process Launch sets goals, roles, meeting schedule
Strategizing sets conceptual design, risk assessment, development strategy, estimates
Planning sets detailed plans and QA process
Requirements definition sets specifications and mechanisms for requirements change
Design sets standards, product design, test plans, and performs reviews, inspections
Implementation completes low-level design, coding, reviews, inspections, testing

10. The Team Process continued
Integration and system testing tests and validates product, produces documentation
Postmortem evaluates experience, analyzes process, provides suggestions for improving
Team roles:
Leader
Development manager
Planning manager
Quality/process manager
Support manager