Three 15 minute videos with John Seddon, talking about the Vanguard method:
Service is different to manufacturing. In simple terms, there is inherently greater variety in customer demand, hence the need to design to absorb that variety.
Life just isn’t always consistent and predictable. When we design our apps, one of the guiding principles is to build our software in a way that maximizes the system’s ability to absorb variety. This makes for apps that are still useful when a policy changes, or we now need two copy editors instead of one.