the mission and the technologies necessary to perform the mission, and the transitional processes for implementing new technologies in response to the changing mission needs. This definition emphasizes the use of the architecture as a rich strategic information source for the improvement of business processes and development of needed information systems. If defined, maintained, and implemented effectively, these institutional blueprints assist in optimizing the interdependencies and interrelationships among an organization's business operations and the underlying IT that support operations. Having read the definition of functional software architecture at the beginning of this entry we can see a functional software architecture as a type of enterprise architecture that can be used as a rich reference for the development of an integrated information system. Naming it a functional software architecture encourages practitioners to use it as a strategic input for a technical architecture. A formal mapping between functional software architecture and a type of ADL is therefore needed. In this way, the formal use and reuse of enterprise architectures as strategic input for software architectures can be realized. Development As the boundary of an enterprise is extended, it becomes increasingly important that a common "big picture" of needed business, people and IT system activities is developed and shared by all the parties involved. A functional software architecture does this by breaking down the organization in business functions and corresponding IT needs. In this way, the enterprise engineer provides a rich schematic reference that can be used by the software engineer in the development of these IT-systems. The development of a functional software architecture can be done by a number of (combined) methods and techniques. Filling in the "gap" between the enterprise engineers and software engineers through the use of different combinations of methods and techniques will be the main objective. However, this objective can only be reached when combined methods result in clear and rich functional software architectures that are developed and used by both parties. Optimizing the internal and external business processes through process reengineering is one of the main objectives an enterprise can have in times of high external pressure. A business process involves value-creating activities with certain inputs and outputs, which are interconnected and thereby jointly contribute to the outcome (product or service) of the process. Process reengineering covers a variety of perspectives on how to change the organization. It is concerned with the redesign of strategic, value-adding processes,