7 posts
Most teams fix defects and move on. The same defects come back.
Every team has that one defect that keeps coming back. An off-by-one in pagination. A missing null check in the auth middleware. A race condition in checkout…
Multiple studies across IBM, AT&T, HP, and Microsoft confirm informal code review catches roughly a quarter of defects.
Informal code review catches between 15 and 30 percent of the defects present in the code being reviewed. That is not an opinion. It is a finding that has been…
Most review checklists are copy-pasted lists of good intentions.
If your team has a code review checklist, there is a decent chance it lives in a wiki page nobody opens. It probably says things like "check for off-by-one…
Fagan inspections need four to six people and two hours to review 250 lines.
A full Fagan inspection needs a moderator, a reader, two to four inspectors, and the author. The team spends two hours reviewing roughly 250 lines of code at…
Michael Fagan's structured inspection process at IBM caught nearly all defects before they reached a compiler.
In 1976, Michael Fagan published a paper in the IBM Systems Journal that described a review process so effective it became the gold standard for software…
Even senior engineers catch only a fraction of defects in unstructured review.
Two senior engineers review the same pull request. One flags a missing null check. The other spots a race condition in the cleanup path. Neither finds both. If…
Informal code review catches 15-30% of defects. Fagan inspections, a structured 50-year-old process, consistently report 60-90% removal rates.
Most code review catches between 15 and 30 percent of the defects it was supposed to find. That is not a guess. IBM measured it in the 1970s, and studies at…