1. A method, the method comprising: generating a model of an IT system that models policies for deploying, configuring, and operating the IT system, the model comprising type declarations in the typing syntax of a declarative language, where the type declarations together model the policies for configuring and operating the IT system, and where the type declarations declare types of classes/components of the IT system, types of relationships between classes/components of the IT system, and constraints of the IT system; and storing the model in computer readable medium.