A Phased System Development Project
The chart on the next page shows a typical system development project, with the project phases matched to the system development lifecycle. This example was the standard for major NASA system engineering projects for many years.

Note the specific reviews called out at the phase gates, essential to ensure the technical capability and safety of the system under development.

Acronym Definitions:

SRR   =   Specifications and Requirements Review

PDM   =   Preliminary Design Review

CDM   =   Critical Design Review (designs are frozen after this milestone and revisions require formal change orders.)