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2 / 7 Show Caption + Hide Caption – Preventive maintenance is good, but AMSAA's study showed that medium tactical vehicles were being serviced nearly 5,000 miles sooner than needed, tying up mechanics and not improving safety in any measurable way. (Graphic by U.S. Army Acquisition Sup... (Photo Credit: U.S. Army) VIEW ORIGINAL
3 / 7 Show Caption + Hide Caption – A hub odometer on the rear wheel of an M1092 trailer (in the Family of Medium of Tactical Vehicles) belonging to the 25th Transportation Company, Schofield Barracks. AMSAA used hub odometers, which track how many miles the trailer has covered, to com... (Photo Credit: U.S. Army) VIEW ORIGINAL
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5 / 7 Show Caption + Hide Caption – The results of the project worked well enough for the 25th Transportation Company that the unit petitioned to continue using the trial schedule with its longer service intervals and condition-based maintenance while the Army studies their wider appli... (Photo Credit: U.S. Army) VIEW ORIGINAL
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The 25th Transportation Company moved from an "every X months" preventive maintenance schedule to servicing vehicles as needed as part of an AMSAA study. Soldiers strengthened their ability to troubleshoot and repair precise problem areas instead of replacing whole parts, and the unit saved time and money.

Soldiers performing preventive maintenance on their M4 carbines disassemble, inspect, clean and reassemble the many parts to ensure that their primary weapon will fire properly during close combat operations. Readiness plans for the hundreds of thousands of Army ground vehicles require just as much attention. Yet the process of performing preventive maintenance for Army vehicles is enormously more complex.

Today's vehicle systems are built with expensive components, electronics and subassemblies that demand properly trained operator and maintenance personnel keenly aware of the performance of their vehicles. However, the man-hours, resources and costs needed to accomplish proper preventive maintenance for Army vehicles have led to concerns among the Army sustainment community over the efficiency of the process. It's the worst-kept secret in Army maintenance units that the Army has been over-maintaining its equipment and that its processes are not very efficient. However, the Army's official policy gives little room to sidestep scheduled service responsibilities. Those concerns about inflexible maintenance schedules led the Army G-4 to formally request that the U.S. Army Materiel Systems Analysis Activity (AMSAA) assess Army preventive maintenance policy, methodology and execution. The study, which ended in February 2018, examined traditional scheduled maintenance practices and policies, focusing on current maintenance intervals and prescribed functions, and determined that yes, preventive maintenance policy and execution could be greatly improved. Each of the Army's more than 400,000 tactical wheeled vehicles has a preventive maintenance requirement, so getting the process correct will pay huge dividends across the Army.


In the study, AMSAA compiled real-world data to quantify the current volume of preventive maintenance actions for the Army's fleet of wheeled vehicles. Vehicle maintenance data collected through the Army's Sample Data Collection and Analysis Program from 2014 through 2016 indicated that approximately 97 percent of the tactical wheeled vehicle fleet and 98 percent of the 1,310 instrumented Strykers were being serviced based solely on time rather than actual use. Semiannual, annual and biennial services dictated through Army maintenance policy were being performed to replace fluids and vehicle parts well before their condition would warrant maintenance attention.

For a fleet of vehicles in which approximately 95 percent of equipment is characterized as "low-usage" or driven less than 3,000 miles a year, premature maintenance actions presented an excellent opportunity for potential improvement in the Army's sustainment strategy.

AMSAA partnered with the U.S. Army Tank-Automotive and Armaments Command (TACOM); the U.S. Army Research, Development and Engineering Command's Tank-Automotive Research, Development and Engineering Center; the U.S. Army Combined Arms Support Command; the Program Executive Office for Combat Support and Combat Service Support (PEO CS&CSS); and the 25th Transportation Company of the 25th Infantry Division at Schofield Barracks, Hawaii, to conduct the two-year project. The project focused on improving service strategies for wheeled vehicles at field-level maintenance sites. The objectives of the study were to reduce maintenance burdens with no detriment to safety, reliability or readiness; realign resources from activities that don't add value to those that do; reduce costs; and reduce waste from premature disposal of components that were still functioning properly.

In the initial phase of the study, the semiannual and annual preventive maintenance intervals were extended to 24 months and the impact on safety, repair and maintenance resources was assessed. The extended maintenance interval would allow for additional vehicle usage that would more closely align with the mileage triggers for preventive services. The study mandated 10-mile road exercises every 30 days for vehicles and every 90 days for trailers, to alleviate any perceived risks to vehicle performance due to the extended service intervals. The road exercises mitigated the risk of unexpected component failure by requiring each vehicle and trailer to be run through less time-consuming quality assurance and quality control checks to check for seal deformations, lubricate gaskets, and charge batteries on a regular basis.

In addition, researchers implemented pre-dispatch checklists that required qualified maintenance personnel to lay eyes and hands on key components such as steering linkages, suspensions and fluid systems at least monthly. Operators, supervisors and maintenance technicians all bore responsibility to validate the current state of each piece of equipment.

The extended services strategy led to an annual savings of approximately $69,000 in service parts in the 25th Transportation Company, on such items as engine oil, transmission fluid, filters, seals, wheel bearings, belts and brake shoes. Adopting similar service strategies for the total Army's fleet of Palletized Load System, Family of Medium Tactical Vehicles (FMTV) and Heavy Expanded Mobility Tactical Truck platforms has the potential to save the Army $47 million annually.

More importantly, 6,100 man-hours were freed within the 25th Transportation Company for unscheduled, deferred and other preventive maintenance necessary to maintain operational readiness of the unit's equipment. Despite initial concerns from maintenance personnel about not being able to properly maintain their equipment due to the extended service intervals, repair data showed there was no increase in part wear or failure, nor was there any measurable negative impact to safety, readiness, availability or reliability.


The 25th Transportation Company's participation in the study presented an excellent opportunity to introduce condition-based maintenance enablers for the unit's fleet of tactical wheeled vehicles and trailers. Condition-based maintenance monitors vehicle health, maintenance and usage data to provide actionable information to improve maintenance and fleet management decisions. The Army is expected to begin the process of adopting condition-based maintenance for all vehicles in FY19, so AMSAA seized on the opportunity to leverage its time working with the 25th Transportation Company to highlight the use of condition-based maintenance in an operational unit. AMSAA worked directly with the 25th Transportation Company to install digital source collectors on 91 vehicles and hub odometers on 91 trailers to provide vehicle health and usage data. The digital source collector is a device connected to the controller area network of Army tactical wheeled vehicles and Strykers that records more than 80 data elements from various electronic control units on the vehicle. The digital source collectors collect and store fault and performance data from engines, transmissions, starters, engine control modules, transmission control modules, braking systems and tire inflation systems, among others, so it can be downloaded and analyzed. Hub odometers are mounted on trailer axles and use the wheel's rotation to determine mileage traveled.

AMSAA field analysts and 25th Transportation Company maintenance personnel downloaded the data weekly and used it to assess the condition of the vehicles and prioritize part orders and repairs necessary to return the equipment to mission-capable status. Most of the electronic non-mission-capable fault codes would be invisible to the Army without the data from the digital source collector. Condition-based maintenance makes these fault conditions visible, helping maintenance personnel better understand conditions affecting vehicle operation and focus on specific repair actions instead of costly component replacements. Depleted diagnostic skills within field-level maintenance units over the last 10 to 20 years have produced a culture of remove-and-replace versus troubleshoot-and-repair. Maintenance personnel able to understand and leverage error faults are able to confidently make subassembly repairs instead of simply replacing major subsystems. The 25th Transportation Company has not replaced a single engine since the beginning of the study, thanks to the fault code information gained through condition-based maintenance.

What was quickly evident with the use of condition-based maintenance during the study was the need for additional training for unit maintenance personnel on how to interpret the digital source collector codes. AMSAA provided unit technicians with diagnostic training and technical support needed to configure diagnostic devices as well as troubleshoot and isolate electrical faults coming from the digital source collectors. After a series of classroom lessons and hands-on diagnostic exercises, technicians could understand error fault codes and systematically track the issues to perform the correct repair.


Maintenance personnel with the 25th Transportation Company went from using zero fault codes during vehicle inspections before digital source collectors were added, to up to 70 fault codes a day; diagnostic and component failure information quickly became a valuable maintenance resource that Soldiers never knew existed. Soldiers reported newfound confidence in their ability to correctly diagnose issues and save both time and money in the repair process. However, the increased visibility into vehicle faults also brought an increase in repairs needed to maintain operational readiness. Condition-based maintenance enablers such as the digital source collectors, laptops connected to onboard vehicle networks and diagnostic software products made Soldiers more informed, but they also made them much busier. Maintenance units will desperately need the maintenance man-hours freed through adoption of optimized preventive maintenance as the Army moves to fully implement condition-based maintenance across all its sustainment units. Optimized preventive maintenance greatly benefits the Army without the use of condition-based maintenance enablers, but repairs identified by condition-based maintenance cannot be performed without the resources returned through the optimized (longer) service intervals.

Expanding time and cost savings experienced within the 25th Transportation Company to other Army maintenance units will require a change to official policy that documents the preventive maintenance process and its current timelines. AMSAA materiel systems analysts led the way in the maintenance policy review and documented recommendations in an updated Maintenance of Low-Usage Equipment section of Army Regulation 750-1, "Army Materiel Maintenance Policy."

AMSAA's recommendations seek to formalize the extended service intervals, quality control inspections, quality assurance reviews and pre-dispatch checklists for nondeployed, low-usage equipment. AMSAA vetted its final version through TACOM, which concurred with the changes and delivered a final version to the Army G-4 for final approval. Army G-4 is currently reviewing the suggested changes to the policy.


The benefits highlighted in the extended services study were immediately apparent with the 25th Transportation Company, and continue to generate additional attention across the Army. The 25th Transportation Company petitioned the G-4 to continue its exemption for the use of extended preventive maintenance intervals. The G-4 granted the request, permitting the 25th Transportation Company to continue to operate on the extended services schedule as new policy is being considered.

Additionally, TACOM has engaged the original equipment manufacturer of the FMTV in a review of the preventive maintenance strategy for that platform. The objective is to benchmark the manufacturer's recommended service schedules and determine changes to the FMTV's preventive maintenance process to decrease life cycle costs and optimize service intervals. Historical fault codes collected by AMSAA will be combined with operational requirements for the FMTV to produce recommended optimized service intervals. TACOM has also identified the Stryker combat vehicle as a potential beneficiary of the optimized service strategy as well.

AMSAA has since partnered with the Army Study Program Management Office, within HQDA G-8, and the 1st Squadron, 2nd Calvary Regiment headquartered in Vilseck, Germany, to undertake a similar optimized preventive maintenance study focused on its Stryker platforms. The study began in February 2018 and is proceeding through the fall of 2019, following an implementation plan similar to the one used with the 25th Transportation Company.

Initial findings have identified reductions in required services, savings in service parts and an increase in personnel man-hours for unscheduled maintenance actions. Final study findings will be briefed to TACOM and PEO CS&CSS in September 2019 at the conclusion of the two-year study, and will be used to support formal recommendations for updated Army maintenance policy.


Initial concerns over the efficiency of the Army's preventive maintenance policy led to a new approach to sustainment operations. Implementing an optimized service strategy that removes the requirement for premature time-based services proved to be a wise, cost-saving approach that also returned valuable man-hours to Army maintenance personnel to support operational readiness repairs.

The new approach is quickly generating additional support throughout the Army sustainment community and, most importantly, with those who set official policy. Data supporting the adoption of updated sustainment processes for today's complex systems will ultimately prove to benefit tomorrow's systems and the Soldiers they support. Savings in costs, resources and maintenance man-hours with no change to safety is a winning formula the Army can live with, and fight with into the future.

For more information, contact the author at or go to

MR. KEVIN GUITE is a lead operations research analyst with at Aberdeen Proving Ground, Maryland. He holds an M.S. in computer science from the University of Maryland Graduate School and a B.S. in computer science from the University of Maryland, Baltimore County. He is Level III certified in engineering and Level I certified in program management. He has been a member of the Army Acquisition Corps since 2008.

This article will be published in the October-December 2018 issue of Army AL&T magazine.

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