Justification

Introduce the situation
1. lab owner building that leaks heat.
2. Need to control the temperture, provide requirment
3. But lab is actually variable. conditions change (perturbation)
4. A robust controller C meets the requirement for all plants in the set P
This is doable with the model of the controller
1. But is this the same with an actual controller?
2. No. There is some layers of abstraction removed in making a real unit