From my POV as an infrastructure architect I have my little motto of "the four pillars":
(In any order)
User those 4 as key points for selecting projects, vendors and implementation paths for nearly anything that comes up at work. Doesn't matter if your looking at replacing your routing topology or looking at implementing a new remote access device...
And they nearly always tie in with the overall business goals too in terms of what they want from an IT department. (which is generally secure, flexible and reliable platforms to exchange data...)