This book is addressed to IT decision makers who face the task of securing and exploiting the overall potential presented by their information systems despite budget constraints. It concerns itself with the task of establishing IT governance processes that ensure comprehensive control as one moves from strategic pl- ning to operational implementation. This task demands orien- tion and transparency, i. e. a management information system for the CIO. Such a system is available in the form of enterprise architecture (EA). EA delivers clear answers, it reveals deficiencies, illustrates the complex interaction of business processes, applications and infrastructure, and provides a foundation for the kinds of analysis that give us the right information and enable genuine IT gov- nance. The term IT governance is more than a mere buzzword. As an IT executive, one may sense that ones information systems are out of kilter and that it will be necessary to take action to avoid - ing treated as if one were a magic orange that continues to yield 1 juice no matter how often it is squeezed. While governance (or control) sounds like the right response, it is not clear where we should begin. Do we know exactly where the gears need lub- cation? Do we know where the rust has taken hold? The reports from the IT jungle are full of examples of tech- logical frivolity, heterogeneous infrastructure environments, se- ers running below capacity, redundant hardware, and superf- ous development tools.