1 REVIEWS A Standard Form of Quality Assurance

2 Major Alternatives for QA proof of correctness review code testing

3 Proof of Correctness mathematical proof of correctness formal verification, symbolic execution,... manual with machine support applicable to source-code, formal specs effective: guarantees compliance with pre- and post-condition, etc. not widely available in practice not easy to scale up to larger projects

4 Review realistic assessment of product quality manual, people driven applicable to all results & documents applicable in all phases of the life-cycle helps to spot problems early effective (30% to 80% of problems are found) finds the problem, not only the symptom complements code testing

5 Code Testing find and eliminate errors based on test-cases computer based applicable to a executable system typically starts with implementation detects errors relatively late effective on the code level finds the symptom (error in result, behavior) complements reviews

6 Review - Basics goal - product assessment –focus is the product –this is not a review of individuals or teams –assessment = relative measure style - teamwork –developer team (authors) –reviewer team –nobody is his/her own reviewer

7 Review - Prerequisites common interest in quality teams are not opponents but partners open brainstorming atmosphere participants “play a role” participants must learn how to handle a review a review must be properly organized time and money must be allocated

8 Review - Responsibilities developer team –present and explain material –answer questions –correct any problems found reviewer team –evaluate quality of material –point out and qualify problems –make a “go” / “no-go” decision

9 The reviewer team is not responsible for the product (development, time, money, error correction, deadlines, etc.). The reviewer team is responsible that the reviewed product has the necessary level of quality before it passes on to the next stage of development.

10 The Reviewer Team typically four to seven team members team members must have the necessary skills to play their “role” team members prepare for the review each team is selected by a team leader for a specific occasion (milestone in a project) from outside of the developing department

11 The Reviewer Team - Team Leader senior engineer or manager not a line-manager (for the developer team) organizes the review and its preparation supervises and guides discussion assures productive working atmosphere checks completeness and timing prepares report

12 The Reviewer Team - Technical Expert senior engineer - “expert” is the authority on issues of methodology and technology in the application domain not involved in the development process checks completeness, consistency, and feasibility of the proposed technical solution puts technical alternatives on the table not the “problem solver”

13 The Reviewer Team - Implementers representatives of the team running the next development phase - experts in further refining a product like the one under review not involved in the current phase of the development process check adequacy of the given material to form a basis for further development help to avoid the “I have just one more question” syndrome

14 The Reviewer Team - Independent Reviewer experienced reviewer focuses not only on the product, but also on the review process itself discusses the completeness of the review “checks the checklists” asks questions going beyond the product asks the “dumb” question (good position for a novice to learn)

15 The Review Process select a team-leader select a team prepare the review run the review prepare a report follow up on open questions

16 End of Section 4d coming up: code testing