Command-and-control managers worry about meeting specifications: service-levels, service standards and so on.
Systems thinkers worry about reducing variation, making things more predictable. Less variation means better quality and fewer losses.

Reducing variation is the secret behind the extraordinary achievements of Japanese manufacturing in the latter part of the twentieth century. Reducing variation leads to components, assemblies and products that work better and for longer. In manufacturing, this means making things more and more alike.

The same principle applies to service organisations. But in service organisations, the principle of reducing variation is turned on its head: it means being able to serve each and every customer the way they want to be served; it is to make the service more and more able to deal with variety.

And there is the paradox: by being able to deal with greater variety, variation in performance reduces. The tool heads will tell you the way to reduce variation in service organisations is to standardise the work, they couldn’t be more wrong.