Many KM projects get funded on a business case built upon saving staff time. You know, "Fred costs the enterprise $32/hour, we're going to trim 5 hours a week that he spends inefficiently searching for stuff, thus saving the enterprise $8k a year per Fred." It's not just KM. Usability guru Jakob Nielsen is infamous for calculating that bad usability costs the world into the billions, and nearly every CMS "ROI calculator" tempts you to include labor savings. In some cases -- like outsourced HTML conversion -- there are real expenses to be axed with a CMS. But in an excellent review of "time savings," Prof. Michael Koenig argues that KM justifications ultimately have to revolve around better decisions and improved performance. Same goes for CMS. The webmaster typically doesn't go away. She just contributes more to the enterprise by working on increasingly specialized (and ultimately more important) tasks -- probably the ones she was trained for in the first place...
Read Koenig's Piece in KMWorld