Samuel C. Phillips, Apollo Program Director, listed the six key checkpoints in the development of Apollo hardware:

1. Preliminary Design Review (PDR)
2. Critical Design Review (CDR)
3. Flight Article Configuration Inspection (FACI)
4. Certification of Flight Worthiness (COFR)
5. Design Certification Review (DCR)
6. Flight Readiness Review (FRR)

These were further defined as follows:

1. Preliminary Design Review (PDR) - a review of the basic design conducted before or during the detailed design phase.
2. Critical Design Review (CDR) - a review of specifications and engineering drawings preceding, if possible, their release for manufacture.
3. Flight Article Configuration Inspection (FACI) - a comparison of hardware with specifications and drawings and the validation of acceptance testing. FACIs could be repeated to ensure that deficiencies had been corrected. Also, this inspection would be conducted on every configuration that departed significantly from the basic design. Items successfully passing the FACI were accepted, provided they met requirements in the Apollo Configuration Management Manual.
4. Certification of Flight Worthiness (COFR) - to certify that each vehicle stage or spacecraft module was a complete and qualified piece of hardware.
5. Design Certification Review (DCR) - to certify that the entire space vehicle was airworthy and safe for manned flight. DCRs would formally review the development and qualification of all stages, modules, and subsystems.
6. Flight Readiness Review (FRR) - a two-part review, scheduled for each flight, to determine that both hardware and facilities were ready. Following a satisfactory ERR, and when decided upon by the mission director, the mission period would begin (which would commit deployment of support forces around the world).