After a decade and more than $500 million in costs, the Defense Department's new travel booking system doesn't work, it doesn't save money, and most staff members don't use it, a new study says.

A Government Accountability Office report released yesterday slams the Northrop Grumman-designed Defense Travel System and calls Pentagon estimates of usage and cost savings into serious question. So poor is the Pentagon's analysis of the system's merits, the report says, that defense officials offered a credit card company news release as sole proof for its claim that the system saves millions of dollars each year.

"We requested, but the [Pentagon] could not provide, any analysis of travel data to support the assertion" of savings, the report says. Further, it says, "The department does not have reasonable [data] to measure the extent to which DTS is actually being used."

This is the second GAO report on the travel system, whose delays and cost overruns have made it subject to repeated attempts in Congress to kill it. Launched in 1998, the system was supposed to have been fully operational four years ago, yet as of this year it was difficult to tell who was actually using it, the report says.

Northrop Grumman spokeswoman Janis Lamar said the company has not yet had time to review the report. But she said, "We built a great system, and it's saving money." She said the system has been deployed to all 270 major military installations and is being used today by over 50,000 personnel on a daily basis.

"It's been a pig," said Sen. Tom Coburn (R-Okla.), chairman of the Senate Homeland Security and Government Affairs subcommittee on federal financial management, who is trying to kill the travel system contract.

The Defense Department has spent more than $500 million on the program since 1998, an overrun of about $200 million, according to figures compiled by Congress from GAO and Defense Department reports.

"It's one big mistake after another . . . that Congress hasn't paid attention to because of very effective lobbying by the contractor," Coburn said. Los Angeles-based Northrop Grumman has spent $72 million in federal lobbying efforts since 1998, Political Money Line reported, and contributed $6.2 million to federal candidates and parties over the past 10 years, according to the Center for Responsive Politics.

Northrop "ought to give some of our money back," Coburn said. "Even if [the system] rolls out, it's never going to pay for itself. It doesn't even get the best fare."

The system was born of a 1995 Pentagon task force recommendation to replace the department's outmoded, chaotic travel procedures with one standardized system for booking official travel, from airlines to hotels. But technical problems have foiled efforts to coax employees to use it.

The Pentagon estimates that the system will save $54 million a year, mostly by automating work once handled by employees. The report calls that estimate "unrealistic," partly because staff would be reassigned, but mostly, because the Pentagon could provide no backup for its claims.

Asked for proof that its system would save $31 million yearly in personnel costs, the Pentagon provided a copy of an American Express news release that discussed savings achieved through a completely different booking system, in a private company.

In a written response to the report, Undersecretary of Defense David S.C. Chu strongly objected to criticism of the Pentagon's estimates of personnel cost savings. "The Department is facing an enormous challenge and must successfully prosecute today's war while still making investments that safeguard the future," he wrote.

"It's time to close this program down," said Sen. Norm Coleman (R-Minn.), who chairs the Senate's Homeland Security and Governmental Affairs Committee's investigations panel, which held a hearing last year on the bill.

"DOD has spent more than 500 million of American taxpayers' dollars on a travel system that was supposed to save money . . . It's an unconscionable waste."