In recognition of differences among projects and Centers, NPR 7150.2 allows flexibility in the implementation of many of its requirements. These SWEs are marked as P (Center) in NPR 7150.2, Appendix D, Requirements Mapping Matrix. "P (Center)" can be conventionally read as "partial, Center determined". See SWE-140 for guidance on two methods for developing approved subsets of these requirements.
The Office of the Chief Engineer (OCE) maintains the review and concurrence approval of acceptable partial requirement sets at the Centers for the following reasons:
- To monitor and control the use of NASA engineering policy.
- To maintain periodic oversight of compliance with engineering requirements throughout the Agency and its contractor community.
- To gain or give insight into appropriate partial implementations.
The flexibility provided by locally designated subsets of Agency software requirements enables tailoring of these requirements based on results of acceptable risks versus resources trades that are to be performed by Center engineering organizations or the Engineering TA (Technical Authority).