The itSMF UK Problem Management SIG are currently writing a white paper on this topic...measuring the value of Problem Management. We've interviewed the likes of Centrica, Oxfam, Northumbria Water and HSBC for input. The paper is lined up for June publication. If you can't wait that long then get in touch with me via LinkedIn or the itSMF office and we'll see what we can do.
Chair, Problem Management Special Interest Group