Reviews & Inspections ... there is no particular reason why your friend and colleague cannot also be your sternest critic. Jerry Weinberg

What Are Reviews? a meeting conducted by technical people for technical people a technical assessment of a work product created during the software engineering process a software quality assurance mechanism a training ground

What Reviews Are Not A project summary or progress assessment A meeting intended solely to impart information A mechanism for political or personal reprisal!

Rationale for Software Technical Reviews Software development is error-prone process (later errors detected, higher the cost for repair) Not possible to test all software Cannot do exhaustive testing; Cannot test specification or high level design Reviews are a form of validation Aid in tracking project Provide feedback Educational aspect – better understanding of software; learn additional technical skills Impact on morale – provides visibility of work; some see as intrusion Impact on maintainability – force incremental documentation

The Players review leader producer reviewer recorder standards bearer (SQA) producer maintenance oracle reviewer recorder user rep

Planning for the Review 1. Select participants 2. Schedule review 3. Develop agenda

Conducting the Review 1. be prepared—evaluate product before the review 2. review the product, not the producer 3. keep your tone mild, ask questions instead of making accusations 4. stick to the review agenda 5. raise issues, don't resolve them 6. avoid discussions of style—stick to technical correctness 7. schedule reviews as project tasks 8. record and report all review results

Review Options Matrix * IPR WT IN RRR trained leader agenda established reviewers prepare in advance producer presents product “reader” presents product recorder takes notes checklists used to find errors errors categorized as found issues list created team must sign-off on result IPR—informal peer review WT—Walkthrough IN—Inspection RRR—round robin review (no face to face meeting) no maybe yes no yes no yes no maybe *

Sample-Driven Reviews (SDRs) SDRs attempt to quantify those work products that are primary targets for full FTRs. To accomplish this … Inspect a fraction ai of each software work product, i. Record the number of faults, fi found within ai. Develop a gross estimate of the number of faults within work product i by multiplying fi by 1/ai. Sort the work products in descending order according to the gross estimate of the number of faults in each. Focus available review resources on those work products that have the highest estimated number of faults.

Metrics Derived from Reviews inspection time per page of documentation inspection time per KLOC or FP inspection effort per KLOC or FP errors uncovered per reviewer hour errors uncovered per preparation hour errors uncovered per SE task (e.g., design) number of minor errors (e.g., typos) number of major errors (e.g., nonconformance to req.) number of errors found during preparation

Inspection checks

Inspection rate 500 statements/hour during overview 125 source statement/hour during individual preparation 90-125 statements/hour can be inspected Inspection is therefore an expensive process Inspecting 500 lines costs about 40 man/hours effort = $5600