In the late 1980s, the term “Lean” was used to describe Toyota’s approach to manufacturing. If you are interested in learning about Lean, I highly recommend the Lean Enterprise Institute, which is dedicated to “advancing Lean thinking throughout the world.” (Here’s their “What is Lean” page.)
What’s more, the book Lean IT is one of the best books I’ve read about IT. It takes general Lean concepts and applies them to IT specifically. There is even a section about service management and a chapter about Lean IT project management!