I discovered my notes from The Machine That Changed The World. It made me think about about the differences between Lean and Agile. A good place to start is to think about the different ways we make things.
Lean came first to address waste in manufacturing, Agile came later as a response to managing complexity of software development. From the Agile Insights Blog:
Conceptually Agile is a subset of Lean principles and practices which are in turn a subset of Systems Thinking.
Once an organisations starts running Lean or Agile principles the whole nature of the organisation starts changing from a static hierarchy to a fluid learning culture. Not all organisations are ready for it, and implementing it in practice can be hard because the consequences of implementing Lean or Agile threatens existing functions and job roles.