Originally Posted by
exerda
I'm not sure it's just site load. Having run into last-minute integration issues on production systems before--and no, it's not fun 4 hours into an after-hours deployment to realize there's a difference between the test and production environments which is breaking things--I can empathize with UA. I'm just not sure their testing was as thorough as it should have been...
I do this kind of thing for a living. Once a system gets beyond a certain size, there is never enough testing done.
Unless you have a budget that allows you to fully duplicate all three production environments (PMUA, PMCO, and the new system), you will have issues. And even then, how do you test all possible possible permutations?
I am not saying that it is not possible to test this enough, just that it is usually way too costly.