The complexity in the IT sector has become nearly unmanageable for many companies. Stagnant IT budgets on one hand and the demand for high flexibility in information technology on the other require a methodical reduction of complexity in IT architectures. Michael Durst presents static and dynamic methods for structuring and managing complex IT architectures, as well as models for the abstraction and description of IT architectures, and illustrates the causal relationships of measures for complexity reduction. He describes key figures for assessing the quality and maturity of IT architectures and their processes in management, as well as the long-term assurance of strategic compliance. Using self-developed software, he demonstrates ways to implement the models and methods within companies. The book is aimed at lecturers and students of business administration.