Wherever software is being built it is done because of an external driver. Typically this driver is a business, although it might also be a personal desire to change the world in some way. It is not generally acknowledged that any effort spent on software development should support this higher purpose. In Lean programs the focus is often on eliminating waste, but it is much more important to improve the flow through the value chain.
Whenever you're developing software.
Beware of improving efficiency if the driver is not the business success of the organization. Determine the costs and benefits with respect to the purpose of the software, instead of focusing on the internal cost structure of organization that produces it.
When you focus on flow, it means that you're not focusing on keeping middle management happy or keeping your direct colleagues happy. It could cause you to not fit in.