Berry was speaking at the October meeting of the Federal Labor-Management Relations Council, where OPM also responded to performance management recommendations from September.
Berry said the government's new jobs website is consistently serving 94 percent of visitors. Still, his office is working with federal agencies to extend most job openings for three weeks to accommodate applicants who have had technical difficulties.
"We're getting feedback from users about what's working and what isn't," Berry said.
"User feedback was essential to designing the upgrade, and it's been essential to identifying issues over the last eight days," he said. "We're going to keep working until we get this right."
Justin Johnson, OPM's deputy chief of staff, said recommendations presented at last month's meeting, including new leadership training programs and a performance management integration board, must involve feedback throughout the year from employee representatives and management associations.
"It is really important that we get this right -- the idea is that the labor representatives need to be at the table in some point in the process. We need to figure out where that is for each agency," Johnson said.
The council expressed concern that agencies would deem another recommendation, the quarterly review, as a burdensome administrative task.
"If it's not implemented well, it's not going to add value," Johnson said. "We need to figure out the best way to handle it and make it clear that we're asking for a process that works."
Although the council has not finalized the report, both OPM and the Energy Department have agreed to adopt the recommendations early.
Johnson strongly encouraged other agencies to follow suit and begin implementing the recommendations.
The council's next meeting is scheduled for Nov. 16.