Who do I get to do this?

This is a surprisingly simply question, “who should be in charge of system X or doing task Y?”. You see this question recycled every so often on line in the form of

•  Should the CIO report to the CEO or CFO
•  Who should manage inter site links, Network or Storage?

 Personally I think the correct answer is always “It depends”.

 What I don’t see is the question

“What should I consider when deciding where to assign responsibility?”

This is probably a standard management topic, but one I don’t see discussed in technology very often.  What would you consider?