Demming argues that a lack of understanding of systems commonly results in the misapplication of objectives.
--> Should we have Sustainable Development Systems instead?
The concept of a “mess” (Russel 1974) describes such system of interrelated problems and solutions, where solutions to most problems produce other problems, and weirdly, some problems are in fact solutions to other problems.
In order to deal with this supersystemic "mess" of problems and solutions, we need to develop a schema that helps us understand it's properties and behaviours.
The thermostat is a device that is misunderstood on different levels.
Firstly, as Don Norman points out, people often have a mental model of the thermostat as directly controllable valve.
Turning up a thermostat doesn't simply make it become warmer quicker, it changes the temperature around which the system stabalizes.
Secondly, even if we understand the implications of the thermostat not simply being a valve, we often still misunderstand it as being a controller.
In fact, the thermostat and the heater are in a circular relation, the 'control' lies in the process, not in the device.
Thirdly, there is a second-order feedback loop at play, since the human that turns the button on the thermostat does so in response to their own physiological temperature and homeostatic system.
The thermostat isn't just a box on the wall.
It exists as relations of relations.