Involve Experts
Problem: Code and design inspections are not rigorous enough to be effective.
Context/Forces:
The rationale is that it is useful to involve experts from other projects and domains. Often the people on the project cannot look at it with new eyes, and although newbies help, getting another expert to attend the review definitely identifies the interesting areas that have been hidden.
Resulting Context: Code and/or design reviews have been exposed to other experts with different and fresh insights.
Related Patterns: InvolveNewbies PeerReview
This is one of the CodeReviewPatterns.