WASHINGTON — Most readers know that when a car enters the shop for maintenance or repairs, the garage is likely to call up with suggestions of more work based on problems found when the hood is raised. It's no different for ships, which have far more systems needing constant maintenance and upkeep.

The US Navy prefers to have its ships moving around and operational rather than tied to a shipyard pier, and has been working to shorten the time ships spend in maintenance. Much of the effort is tied to the Optimized Fleet Response Plan (OFRP), a move by the Norfolk-based Fleet Forces Command to reduce maintenance periods and get more operational time for its ships. But the plan is in the earlier stages of being implemented and Navy officials acknowledge it has yet to really bear fruit.

The Government Accountability Office (GAO), tasked by Congress to look into the situation, generally concurred with Navy leaders in a report released Monday. By many measurements, GAO said, it's still too early to gauge the ultimate success of OFRP.

"Thus far, only a small portion of the fleet has entered an optimized cycle, and as a result it is too early to assess the OFRP's overall effectiveness," wrote John Pendleton, GAO's director of defense capabilities and management, in the report's introduction.

"However," he added, "the first three aircraft carriers to enter the optimized schedule have not completed maintenance tasks on time, a benchmark that is crucial to meeting the Navy's employability goals. Further, of the 83 cruisers and destroyers, only 15 have completed a maintenance availability under OFRP."

GAO, echoing Navy officials, observed that "public and private shipyards involved in Navy ship maintenance face a number of challenges in completing maintenance on time, including unanticipated work requirements, workforce inexperience, and workload fluctuations."

The Navy, Pendleton wrote, "has been struggling to accurately define ship maintenance requirements, a step that is key to completing maintenance on time." A new contracting strategy also is complicating the maintenance picture, GAO said.

On the plus side, GAO observed that security protocols, procedures and policies that impeded shipyard work schedules have improved, and noted that most Navy and shipyard officials agree security-related obstacles are no longer an issue.

While GAO documented maintenance challenges in the fleet, it noted that "Navy officials are aware of the challenges faced both by the public [government-owned] and the private shipyards in completing maintenance on time."

The Navy, GAO said, is at work to improve the maintenance process, and service officials have stated "that it will take time for these changes to bring about a positive effect."

As a result, GAO declined to make any recommendations in the report.

Twitter: @CavasShips