A Pearl Harbor Naval Shipyard union leader said a Defense Department plan to overhaul how it evaluates and pays its civilian workforce would hurt morale, productivity and efficiency.

Ben Toyama, vice president of the International Federation of Professional and Technical Engineers Local 121, told a U.S. Senate subcommittee hearing in Honolulu on Wednesday that managers wouldn't be able to implement the plan fairly.

The program, dubbed the National Security Personnel System, is designed to give the Defense Department more flexibility to hire, fire and discipline employees. For example, the plan would allow the department to offer bonuses to those who agree to take hard-to-fill positions.

The new rules would also tie a portion of worker pay to performance to reward those who do well.

But Toyama said the plan would destroy teamwork by encouraging workers to compete against one another.

"The bean counters and the widget counters would force the employees to stop working as a team and start working as an individual to increase the opportunities for promotions," Toyama said.

The program would further threaten safety by discouraging shipyard workers from reporting defects out of fear flaws could hurt their performance reviews and their pay, he said.

The Defense Department plans to start implementing the plan in increments next month, beginning with senior managers.

The program isn't scheduled for the shipyard until next year. But its implementation may be delayed or blocked altogether, depending on how a federal judge rules on a lawsuit unions filed to block the system.

The labor groups argued the program would violate federal law by undercutting workers' right to collective bargaining.

Sen. George Voinovich, R-Ohio, who chaired the hearing in Waikiki, said he believed the Defense Department could address the issues Toyama raised as it rolls out the program.

"This is not cast in concrete. There are changes that can be made to the system that will better accommodate some of your concerns," Voinovich said. "I'd like to know things that you think should be in there."

Sen. Daniel Akaka, D-Hawai'i, said training for the plan would be key. "Getting training right on the front end of the implementation of NSPS could promote greater employee understanding," Akaka said.

There are about 16,000 civilian workers at the Pearl Harbor Naval Shipyard, Hawai'i's largest industrial employer.