WASHINGTON — After months of delays, the newest iteration of the F-35's logistics system is finally ready to be installed on the aircraft, manufacturer Lockheed Martin announced Wednesday.

So far, the U.S. Air Force and U.S. Navy have approved the most recent version of the Autonomic Logistics Information System, or ALIS, a core piece of F-35 infrastructure that enables mission planning, gives step-by-step maintenance instructions and allows personnel to order spare parts, among other functions.

The U.S. Marine Corps, however, is about six weeks away from being able to approve the new ALIS on its short takeoff and landing F-35 variant, the company said.

The biggest change between ALIS 2.0.2 and earlier versions is the integration of the F135 engine made by Pratt & Whitney. This allows maintainers to use ALIS as the sole maintenance system needed to monitor the health of the propulsion system, run diagnostics or conduct repairs.

All versions of the joint strike fighter use the same logistics architecture, but the Marine Corps’ F-35B needed a particular update to the engine’s computing system for ALIS 2.0.2, said Mike Beard, who works F-35 logistics strategy and customer engagement for Lockheed. Pratt & Whitney didn’t have that update done in time for testing at Nellis and Edwards Air Force bases, but have since completed it.

"Now that we have that, we’ll be integrating it [with ALIS], and we’ll be able to roll it out to the Marine sites," he said.

Aside from the engine integration, ALIS 2.0.2 also includes software improvements that will allow for a better connection between deployed ALIS systems and the ones located at home bases, according to Lockheed.

ALIS 2.0.2 has been supporting planes at Nellis Air Force Base, Nevada, since March, and it will gradually be rolled out to operational sites by the end of the year, the company said. The logistics system is already in use at more than 20 locations.

"This upgrade will allow deploying units to predict ‘what if’ scenarios inside ALIS, removing most of the manual planning that is done today," Reeves Valentine, the company’s vice president of F-35 logistics, said in a statement. "ALIS 2.0.2 will allow users to forecast and make those decisions. Picking the best jets, support equipment, spare parts and personnel for the deployment and managing resources throughout their lifecycle — that type of data should ultimately translate to better aircraft availability."

ALIS 2.0.2 was supposed to be complete in time for initial operating capability of the Air Force’s F-35A last August, but integrating the F-35’s engine with the logistics system proved to be more difficult than expected.

As the summer of 2016 began, Lockheed predicted it would take until at least October or November to field the capability. The general in charge of making the initial operating capability declaration — Gen. Herbert Carlisle, then-head of Air Combat Command, who is now retired — ultimately opted to move forward with the milestone without ALIS 2.0.2 on board, stating that F-35 squadrons had proven they could deploy without the capability.

Because of the delays to ALIS 2.0.2, some of the capability for the next version of the system, ALIS 3.0, has been offloaded to the later version, called ALIS 4.0.

ALIS 3.0 is still planned to be fielded in early 2018 in time to close out the program’s system development and demonstration phase. Valentine said the focus of ALIS 3.0 was including key user enhancements seen as critical for wrapping up the system development and demonstration phase — including improved data transfer software that reduces the time it takes to load large files and tools that filter out redundant information — as well as security updates.

The new ALIS 4.0 version will be completed a year later for an early 2019 fielding, he said. Besides further usability enhancements, it will incorporate new capabilities that address, for example, diminishing material supplies.