Sometimes this gets taken advantage of by the vendor. The government doesn't have the ability to design and specify things properly themselves when the deal is

Sometimes this gets taken advantage of by the vendor. The government doesn't have the ability to design and specify things properly themselves when the deal is signed. The vendor might know that things are wrong at that point but wait until afterwards to point out all the problems and correctly claim changes in scope and requirements at significant expense. At least I was told that happened on the California rail project.