The analytical approach employed by both BSP and BISC is "top down". The implications of the words "top down" are multiple and varied, and all apply … - John Zachman

Although many popular information systems planning methodologies, design approaches, and various tools and techniques do not preclude or are not inconsistent with enterprise-level analysis, few of them explicitly address or attempt to define enterprise architectures. Some examples of such popular offerings include

The Information Age is unfolding just as predicted by many of the sociological prognosticators of this century. Information issues are on everyone’s mind and on multitudes of lips. It is hard to pick up a newspaper or current affairs magazine without seeing a feature on the internet, web pages, e-mail, television terminals or some other new technology. In fact, technology innovation is relentless and escalating and technology stocks continually drive the stock market to high after high. There is no field of human endeavor that is exempt from the onslaught of information technology.

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.