As markets change, business models alter and technology evolves information systems need to change. The ability and speedof change in information systems are crucial success factors for the success of the business itself. We call this IT Agility.IT Agility depends on many internal and external factors of the enterprise and can be achieved through reactive and proactiveactions. In this paper the focus is on the information systems architecture as a main proactive contributor to IT Agility.As measurement is essential for the management of IT Agility a framework is suggested that quantitatively evaluates themain influencing factors of information systems architecture on IT Agility (coupling, redundancy, complexity andparameterization). Results from a real-world application show the ability of the framework to identify fields for improvementin IT Agility in the information systems architecture of enterprises.