Decentralization without structure is chaos. - John Zachman

(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.

A significant observation regarding... architectural representations is that each is of a different nature than the others. They are not merely a set of representations, each of which is an increasing level of detail than the previous one. Level of detail is an independent variable, varying within each architectural representation.

To keep the business from disintegrating, the concept of information systems architecture is becoming less of an option and more of a necessity