At least in my case, I can’t come up with a system that doesn’t suffer from these problems, but still keeps corruption in check.
For example, I was in a bidding process for my own software. Our contract has a legal time limit, afterwards it has to be renewed using the same bidding process as the first time. It makes perfect sense for us not to rewrite our software - it’s working just fine after all. But legally, we’re bidding on rebuilding the entire thing, have to compete with laughably low offers from all over Europe, and when we won the contract we decide, almost by accident, to keep using the old software, but on a very tight budget.
The pragmatic thing would have been, to just extend our contract, but that could mean endless contracts to extremely high prices for software that just happens to be embedded deep enough to be irreplaceable.
black0ut