You can read about the Xerox experience with KM here, including some quantified success stories
Take the equipment problem a Brazilian engineer still couldn’t solve, despite using Eureka, equipment manuals, and the available help. It seemed the only option was to replace the customer’s color copy machine—a $40,000 cost. But before the engineer submitted the equipment order, he decided to check Eureka one more time. A Canadian colleague had entered the solution to his problem into Eureka a few hours earlier, so the potential $40,000 copier replacement became a 90-cent part replacement.
Xerox saw a 10 percent reduction in labor and cost improvement just within the initial Eureka rollout in France. That return on investment jumped tremendously as the company opened the application to its Canadian, European, and South American engineers. Xerox estimates that Eureka has prevented at least 300,000 redundant solutions.
Also from here
we concluded that deploying this capability in the field organizationAlso from here
in France reduced their parts cost five to ten percent, and reduced
time spent at customers’ sites five to ten percent as well. If you dare to
extrapolate that to a worldwide sales organization with 20,000 people
and go at the high end (ten percent), you save, in some way, 2,000 people.
We have ten percent more productivity without adding people. Our
people are now much more effective, faster, and get more work done.
Also, anecdotal evidence shows that customers are much more satisfied.
Interviews with employees say they like this. This, again, is a win-win
situation for everyone.
Since piloting the system in France in 1996, Xerox has launched Eureka in 71 countries and has made it available to the company's entire corps of service engineers. The results have beat expectations. The system currently stores about 50,000 product fixes. Last year alone, it helped solve 350,000 service problems and saved Xerox approximately $15 million in parts and labor.