The Office of Personnel Management has begun surveying more than 500,000 federal employees to measure their job satisfaction.

The Federal Employee Viewpoint Survey — previously known as the Federal Human Capital Survey — will run through mid-March, OPM said Thursday. OPM is inviting about 100,000 more employees to participate than it did in 2008, when it last surveyed the federal workforce.

"In these times of unprecedented change, it is more important than ever to maintain a focus on the federal government's most valuable asset — its employees," OPM Director John Berry said. "Every federal employee plays a role in fulfilling the mission of each federal agency or department. More than ever, their work is critical to the well-being and security of our nation."

OPM said this year's survey will have new questions focusing on employee engagement and work-life issues. The government's chief human capital officers will use that data to assess their agencies' human capital management and decide how to improve it.

OPM stressed that employee responses will remain confidential.

The survey will also ask employees questions about their training opportunities, managers and senior leaders, benefits, schedules and opportunities for advancement.