Are maturity models an effective way to validate the real state of business in terms of processes? Or do you know another mechanism?

Here's an article that discusses how outcomes provide a better measure of your processes than maturity models:

http://blogs.gartner.com/richard-hunter/ma...t-value-itself/

Maturity models sound good, but there is a point where the law of diminishing returns comes into play. Do you stop at CMMI level 3, for example, or push your way through to levels 4 & 5? Are you getting value out of doing so?

You don't need a maturity model to focus on process improvement. A maturity model provides a framework and a structure, which people like because it gives them something concrete to focus on. However, once people stop seeing value in doing all of the work required to get to the next level, it stops. Achieving someone else's definition of the next level of maturity is not always worth the work it takes to get there.

Let's see what others have to share; what is the problem you are trying to solve?