When the wreckage and chaos caused by a legacy infrastructure from the Middle Ages became too much for 19th-century Paris, a career civil servant took charge. Out of twisted medieval streets, Georges Eugène Haussmann carved out miles of wide boulevards, installed a modern sewer and water supply network, and incurred the wrath of Parisians. Even when you're caked with muck and garbage, the idea of change is more appealing than change itself — when you're in the way.

Today's information technology structure of intertwined systems resembles pre-Haussmann Paris. Just as winding alleys can lead to a misshapen city, the mess of federal information technology infrastructure creates an architecture of sorts. It's just not a designed one.

In many cases, technologies successfully support business processes. Some agencies have connections for data exchange. And sometimes technology streamlines business processes and organizations.

Everything that enterprise architecture is meant to facilitate has already happened — after a fashion. "There is an architecture," said Ira Grossman, chairman of the Chief Architects Forum. "We're trying to make it more efficient and interoperable."

Experts say that although the government does its business, today's ad hoc, unplanned architecture is inefficient. Scores of systems that should share data cannot do so, and the government has missed opportunities for improving processes.

"That is the consequence of not doing [enterprise] architecture," said Randy Hite, the Government Accountability Office's director of IT architecture and systems issues.

Still, the practice of charting and planning an architecture often encounters hostility or indifference. After all, management fads come and go. Enterprise architects speak a mind-numbing lingo. Chief information officers are responsible for enterprise architecture, even though its development had nothing to do with IT, said Dick Burk, head of the Office of Management and Budget's Federal Enterprise Architecture Program Management Office, speaking at a conference earlier this year.

"If enterprise architecture doesn't produce results, then it simply is going to be the next thing that gets blown away," Burk said.

Other obstacles are lurking, too.

In concept, enterprise architecture is simple. It creates an opportunity for technology and business employees to collaboratively match mission requirements to an organization's infrastructure, and vice versa. When agencies implement IT, they also need to update their business processes to take advantage of the new capabilities.