DoD is currently going through a major policy overhaul of its instructions tied to the Defense Acquisition System (DAS). Some instructions have been issued and some are still pending and will be issued soon. DoDI 5000.02, effective Jan 2020, will help you as it shows where to find the latest policy to manage programs. It "restructures defense acquisition guidance to improve process effectiveness and implement the Adaptive Acquisition Framework (AAF)."

Currently Systems Engineering is covered in DoDI 5000.02T, Operation of the DAS, but will be covered under DoDI 5000.UJ, “Engineering” once that instruction is issued.

Refer to the following websites for more information.

https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodi/500002p.pdf?ver=2019-05-01-151755-110

https://aaf.dau.edu/aaf/mca-interim/