# Justification 1. 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 2. 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