When the rate of change increases to the point that real time required to assimilate change exceeds the time in with change must be manifest, the enterprise is going to find itself in deep yogurt. Zachman (1994)
(Enterprise Architecture is) the set of descriptive representations (i.e., models) that are relevant for describing an Enterprise such that it can be produced to management's requirements (quality) and maintained over the period of its useful life. Zachman (1987)