Analysts report that the well-being of a major sector of the U.S. economy hinges on an aging and overworked computer located in Newington, Va., a quiet Washington, D.C., suburb. The computer's assigned task is to count imports coming into the U.S. But the system is 15 years old and with imports soaring it stands near collapse, experts warn.

If the computer breaks down for more than a few hours, goods from abroad will start stacking up at the U.S. border. U.S. companies that rely on just-in-time deliveries might have to shut down production. Economists say the ripple effect could cost the U.S. billions of dollars.

• When the computer -- known as ACS for Automated Commercial System -- was first brought on line, U.S. imports stood at $332 billion annually, but are close to $1 trillion now.

• The first sign of trouble came in September 1998, causing a six hour shut down that threw the U.S. Customs Service three weeks behind schedule.

• After a second glitch a little more than two weeks later, the computer muddled along for a two-day period.

• A new system would cost around $1.5 billion -- but the White House, Customs and Congress have reportedly dragged their feet on spending the money.

Several months ago, Customs ran a simulated computer shutdown test in the ports of Charleston, S.C., and Savannah, Ga. Instead of using the computer, officials counted using pens and paper. The result was that backlogs exploded after just six hours.

After a theoretical 30-day shut down, cargoes would have been delayed by as long as eight days in port. Manufacturers would have been deprived of vitally important parts and agriculture imports would have rotted.

Source: Daniel J. Murphy, "A Computer-Age Trade Meltdown?" Investor's Business Daily, September 14, 1999.