WASHINGTON — For the last two decades, U.S. presidents have launched programs aimed at measuring and improving the performance of federal programs.

Although President Barack Obama was the first to create a federal chief performance officer, there so far appears little evidence — at least publicly — that a functioning performance management program has taken hold.

As part of its 2011 budget request, the administration last year rolled out a list of high-priority goals — ranging from improving energy management at NASA to reducing the population of homeless veterans — for individual agencies to meet over the next year or two.

The public debut of a website that tracks progress toward those benchmarks has been delayed, although agencies submit data to the site, Performance.gov. Little other information has been released on agencies’ execution of their goals thus far.

“We don’t know how much they’ve accomplished,” Philip Joyce, professor of public policy at the University of Maryland, said of the administration’s approach. While Joyce credits agencies with generally choosing specific, measurable goals, “it’s still very much a work in progress,” he said.

Administration officials say they plan to do much this year to advance the cause. They plan to identify best practices and develop guidance to help with goal-setting, results reviews, and the use of incentives for improving performance.

Setting priority goals is just one part of the administration’s performance management strategy, which also includes cutting waste, attracting top talent to the federal work force and promoting accountability through open government.

“While we certainly have much left to do, our progress to date gives me a lot of optimism because we’re building momentum,” federal chief performance officer Jeffrey Zients said in November.

At the heart of the performance agenda is the Performance.gov website. By Zients’ description, it is a “one-stop shop” for regularly updated information on agency goals and yardsticks of progress toward meeting the goals.

The government began testing a beta version of the site in August; all 24 agencies covered by the Chief Financial Officers Act are participating, Office of Management and Budget (OMB) spokeswoman Moira Mack said. Although the site was supposed to open to the public by year’s end, that step was delayed to get agency feedback and “to kick the tires a little more,” Mack said.

“It’s proven to be a very valuable tool for tracking progress,” she added.

Performance.gov is the Obama team’s answer to the now-discarded Program Assessment Rating Tool (PART) used by the George W. Bush White House. Although PART succeeded in getting agencies to develop program yardsticks, “ultimately, few agency managers or people in Congress used PART information,” OMB Director Jack Lew said at a Senate confirmation hearing last fall.

Still to be seen is whether Performance.gov gets more buy-in.

At the Senior Executives Association, which represents the government’s top managers, President Carol Bonosaro did not see why executives would not buy in to the White House approach as part of their professional responsibilities.

Bonosaro added, however, that every administration brings its own approach to performance management. “It’s very difficult in the end to honestly believe that what they are implementing right now is going to be long-lasting,” she said.

The Obama administration’s strategy may have gained some statutory staying power with last month’s passage of an overhaul to the 1993 Government Performance and Results Act. In one provision that appears to piggyback on the Performance.gov model, the new law requires creation of a government-wide website tracking progress toward goals.

But the process is still in flux. NASA, for example, “generally anticipates” meeting its goals, spokesman Grey Hautaluoma said in an e-mail. But two goals have been added since the summer, he said. Another has been deferred, and the odds on the agency fully attaining its energy management target are dicey.

Using a 2003 baseline, that goal in part calls for cutting energy intensity — a measure that plots energy use against building size — by 30 percent by 2015.

Although the goal, mandated by a 2007 executive order, led to some energy savings and innovation, NASA has known that “it would not likely be achievable in the stated time frame without increased and sustained funding support,” Hautaluoma said.