Otherwise, as Suresh notes, the only way to eliminate human error completely is to eliminate the presence of humans in the activity. and,hence by reference..... Automated config deployment / provisioning.
That's the funniest thing I've read all day... ;-) A little pessimistic rant.... ;-) Who writes the scripts that you use, who writes the software that you use ? There will always be at least one human somewhere, and where there's a human writing software tools, there's scope for bugs and unexpected issues. Whether inadvertent or not, they will always be there. If the excrement is going to hit the proverbial fan, try as you might to stop it, it will happen. Nothing in the IT / ISP / Telco world is ever going to be perfect, far too complex with many dependencies. Yes you might play in your perfect little labs until the cows come home ..... but there always has been and always will be an element of risk when you start making changes in production. Face it, unless you follow the rigorous change control and development practices that they use for avionics or other high-risk environments, you are always going to be left with some element of risk. How much risk your company is prepared to take is something for the men in black (suits) to decide because it correlates directly with how much $$$ they are prepared to throw your way to help you mitigate the risk .....;-) That's my 2 <insert_currency> over ...... thanks for listening (or not !).... ;-)