It should be obvious to every software project manager, but unfortunately it doesn't always seem to be: System architecture design PRECEDES technology decision-making. Premature, ill-fated technology decisions can bring whole projects down. Or, as Hank Rainwater states in his book "Herding Cats: A Primer for Programmers Who Lead Programmers":
"The magic bullet or golden hammer (whatever you want to call it) technology doesn't solve business problems, people do. Sure, you employ technology to implement a solution, but you are wasting time if you think buying the latest addon to your development environment is going to increase productivity."
"I encourage you to determine your architectural needs and plan a system before you choose a technology of implementation. You'll just have to do it all over again if the new whiz-bang tool doesn't pan out. You've heard it said many times: If you don't have time to do the job right, when will you have time to do it over again?"