history of beer.
We could torture this analogy to the limits by comparing the golden liquid in a mug of beer to the on-going costs of maintaining existing systems, and the frothy head as representative of the available discretionary spend - but I'm likely to lose you in search of a cold one.
Today's CIO's are often challenged by opposing factions in the daily course of the business cycle. The "Tastes Great" crowd wants more taste, i.e. more business capability, more functions, more features, more customers. At the same time, the CIOs are equally pulled by the "Less Filling" voices to reduce costs, inefficiencies, and lower times to market.
The problem is that focusing too much on growth ("Tastes Great") can lead to unrewarding complexity with overlapping systems, slow times to market, and limited innovation.
Listening to the "Less Filling" voices to cut costs can lead to reactive efficiency, in which the organization can only get really good at doing what they've done in the past.
Enterprise Architecture is a discipline that seeks to understand the goals of the corporation in its entirety and balance forces to arrive at both growth and efficiency. Gartner's Applying Enterprise Architecture, states "Properly used, EA is a valuable asset that can drive significant benefits. Until recently, EA’s value has been primarily within IS, to reduce cost and complexity. Of greater value is applying EA more broadly to improve business effectiveness. This requires CIOs to use EA to align IT with the business strategy, communicate IT’s vision and value, guide IT investment and design decisions, and change business and IS behaviors."
The mature use of an Enterprise Architecture function allows and causes an organization's Information Technology to deliver both growth and efficiencies to the enterprise.