One of my relatives attended a training in London about Lean Thinking, although my friend’s domain is aircraft maintenance, I was surprised by the amount of his excitement. I decided to do a little research to know what is the point and know if something similar exist in software development domain.

After a little research I found an article that astonished me (those days I was overwhelmed by the details of big processes in my company). Here is a link to that article, I think you will find it useful, Principles of Lean Thinking at: http://www.poppendieck.com/papers/LeanThinking.pdf.
At first it seemed Lean Thinking is conflicting with CMM/CMMI, but after a little research I found there is no conflict, and we should take care when applying CMMI to be in a beneficial way to the organization and consistent with its size and their projects complexity. See this interesting blog dedicated to agile and CMMI: http://www.agilecmmi.com/.