These are facilitated reviews held at predetermined points in the development process. The objective is to evaluate a system as it is being specified, designed, implemented, and tested.
Checkpoint reviews focus on ensuring that critical success factors are being adequately addressed during system development. The participants are subject matter experts on the specific factors to be reviewed against, and could include customer representatives, analysts, programmers, vendors, auditors, etc.
For example, if system performance was identified as a critical requirement, three checkpoint reviews might be set up at the end of the requirements, design, and coding phases to ensure there were no performance issues before proceeding to the next phase.
Instead of walking team members through a general checklist (as would be done in a phase-end review), a designated performance expert would look specifically at whether performance requirements were being met.