I have no experience of military procurement. However, I did spend many years in the offshore industry, part of which being managing contracts for various services.
The most important thing we found was that the scope of work for the service had to be accurate, measurable and apply to the job in hand. From reading earlier posts, and past comments on procurement, in a lot of cases the people buying didn't do this.
For example, the engines on the Navy's new frigates were COTS items, absolutely fit for purpose for cruise ships, but not the right thing for warships. Who wrote the scope of work / specification, then who let the items be bought and installed and didn't o r wasn't allowed to say 'Hang on a minute....'
Waiting for incoming on this ......