Code inspection—the peer review of proposed code for the purpose of identifying defects—is a powerful technique for removing code defects early in the development cycle when they are inexpensive to remove. In addition to providing cost-effective defect removal, code inspection facilitates knowledge transfer, provides informal training, and encourages developers to write the best code they can because they know it will be inspected.
Checklists significantly improve code inspection effectiveness and efficiency by focusing reviewers on important issues that may otherwise be overlooked. For example, one study presented at the International Conference on Software Engineering, showed a 30% improvement in inspection efficiency when a checklist was used (six defects per hour with the checklist, compared to four or five with other methods).