The purpose of the Safety Assessment Report (SAR) is to document a comprehensive evaluation of the mishap risk being assumed prior to test or operation of a system, prior to the next contract phase or at contract completion.
The SAR documents all safety features of the hardware, and system design and to identify procedural, hardware-related and software-related hazards that may be present in the system being acquired including specific procedural controls and precautions that should be followed.
For small development programs or non-developmental item acquisitions, the SAR may be used as the only formal documentation of safety program activities/hazard assessment. In this case, inexperienced safety engineers often have difficulty deciding if the SAR content is sufficient.
The SAR is sometimes referred to as a SSAR (System Safety Assessment Report). The SAR (MIL-STD-882E Task 301) is not to be confused with the System Safety Assessment (SSA) a la SAE ARP4761.
The SAR and the safety case or safety assurance case are close cousins: not identical - similar, with the SAR being the poor cousin.
We develop damn good SARs and have never received customer comments that required us to modify them.
One of the SARs we developed was for DJM for their Scorpion SEID-17 and SEID-20 run flat extraction and insertion systems. Their customer was the USMC. Another was for Data Transformation Corporation for the Direct User Access Terminal (DUAT). Their customer is FAA. Yet another was for IMS-EMS for the De-Icing System of the Watchkeeper Unmanned Aerial Vehicle (WK450 UAV). Their customer was Elbit Systems.
If you are interested, we can teach you everything you need to know about SARs - more than you will find anywhere else.
There is much more to SARs than is shown in the familiar DIDs (DI-SAFT-80102B or FAA-DI-SAFT-107). HCRQ can provide you a list of what is missing.