GSA Inspector General Brian Miller, left, and Acting GSA Administrator Dan Tangherlini testify during a hearing before Senate Environment and Public Works Committee April 18, 2012 on Capitol Hill. (Alex Wong/GETTY IMAGES)

On his five-month listening tour to determine how the agency tasked with saving the government money reveled in profligate spending that led to scandal, Dan Tangherlini found that the General Services Administration had “lost its focus.”

“There was a really important mission here to fund efficiency and economy in the government,” the GSA’s acting administrator said in his first interview since a Las Vegas spending scandal forced out its top leaders. “But the events that brought me here showed we had lost focus and attention we are supposed to be putting toward driving value.”

On the eve of an appearance scheduled for Wednesday before the Senate Homeland Security and Governmental Affairs Committee, Tangherlini laid out the changes he hopes will “bake into the DNA of GSA” to cut out waste and boost efficiency.

With a small team that included Inspector General Brian Miller, whose report on a four-day, $823,000 conference off the Las Vegas strip made uncomfortable headlines for the Obama administration for months, Tangherlini studied the operations of the GSA, which owns and leases federal buildings and buys much of the federal government’s non-defense supplies. Its budget is $23 billion.

He held meetings with workers at headquarters and the 10 satellite offices — most of them “virtual” to save on travel costs.

He flew to San Francisco, though, to meet with employees in Region 9, where the executive who organized the 2010 Western Regions conference had told his colleagues he wanted to one-up previous events and host an “over-the-top” party.

Tangherlini solicited money-saving ideas from the staff in a program he dubbed the Great Ideas Hunt, with 500 employees weighing in. “You know the people I’ve met who were the most upset about the excesses?” he said. “GSA employees.”

The ideas, from double-sided printing to scrapping an employee survey that cost $1 million, have saved about $5.5 million, officials said.

The first big changes were to rein in travel and conference budgets that had spiraled out of control: In four months, 50 conferences were canceled. The rest of the government soon followed with strict limits on conference spending. Daily reimbursement rates for federal travel were frozen rather than increased, as is customary. Bonuses for top executives were cut, and a hiring freeze was put in place for all but essential hires.

Cutting waste and making government more efficient — these are mantras of the Obama administration’s pledge to create a leaner government. But they were sorely tested last April when Miller revealed in an embarrassing report that executives in charge of federal buildings organized a four-day junket for 300 employees and managers. Attendees, who included top agency officials, were treated to a mind reader, lavish after-hours parties in loft suites and a bicycle-building exercise.

Administrator Martha Johnson was forced to resign, her leadership team was fired and President Obama moved quickly to put a turnaround manager in place, plucking Tangherlini, a senior official at the Treasury Department, to fix a broken GSA. Tangherlini had made a name for himself running the day-to-day operations of the District under Mayor Adrian M. Fenty (D) and served as interim manager of Metro before that.

All told, 11 managers involved in the Western Regions conference were fired, eight employees suspended and eight others admonished, reprimanded or warned, officials said Tuesday. The GSA has also demanded reimbursement from 14 employees and one contractor hired for the event, and the Justice Department is weighing criminal charges against the conference planner and at least one contractor.

At numerous hearings after the scandal, members of Congress described a free-spending culture that allowed managers outside Washington to build fiefdoms with little oversight from Washington.

Tangherlini acknowledged that the agency’s “decentralization may have contributed to a lack of transparency.”

He also said that the GSA may have taken too far a business culture that came from its close work with the private sector.

“We’re dealing with a unique kind of shareholder,” he said. “The taxpayer doesn’t get to divest from this company. Our responsibility to our shareholders is higher, and our level of oversight and accountability has to be higher.”

Tangherlini plans to tell Senate lawmakers Wednesday that the hiring freeze will continue through fiscal 2013.

He is reviewing all agency bonuses, “and there will likely be substantial cuts in those.”

Personnel, information technology, budget, finance and accounting operations are being centralized in Washington to improve oversight of spending. And the Federal Acquisition Service, which handles purchasing for the government, will reduce the fees it charges agencies to buy from a cut-rate list of approved vendors. Tangherlini said the high fees are driving many agencies to buy on their own, spending more money than necessary.

“A lot of people are expecting us to issue some highfalutin report and call it a day,” he said. “But it’s important to engage in a recurring, continuous improvement program.

“Right now, our primary focus is rebuilding the trust of the American people in the organization.”