In 2014 I presented at the Agile Australia conference on how to sustainably improve performance in organisations using the Vanguard Method. InfoQ recorded the session, and they have published it here.
The videos that are used in the presentation can also be viewed in high quality here
We applied Systems Thinking from Vanguard. Systems Thinking is a fundamental way of examining the entire organisation, not just the IT component. It is a method to really understand what matters to the customer, to understand the dysfunction of current methods, measures and metrics, to get people who do the work, to experiment locally to design new ways of working. It is incredibly profound. I could talk another 3 hours just on Systems Thinking!