THE UNIVERSITY OF THE ARMY NATIONAL GUARANTEE 1775
Headquarters
Department of the Army
Washington, DC
25 March 2024

*Army Regulation 702–19

Effective 25 April 2024

Product Assurance

Reliability, Availability, and Maintainability

By Order of the Secretary of the Army:

RANDY A. GEORGE

General, United States Army

Chief of Staff

MARK F. AVERILL

Administrative Assistant to the

Secretary of the Army

History. This publication is a major revision. The portions affected by this major revision are listed in the summary of change.

Authorities. This regulation implements DoDI 5000.88.

Applicability. This regulation applies to the Regular Army, the Army National Guard/Army National Guard of the United States, and the U.S. Army Reserve, unless otherwise stated.

Proponent and exception authority. The proponent of this regulation is the Assistant Secretary of the Army (Acquisition, Logistics and Technology). The proponent has the authority to approve exceptions or waivers to this regulation that are consistent with controlling law and regulations. The proponent may delegate this approval authority, in writing, to a division chief within the proponent agency or its direct reporting unit or field operating agency, in the grade of colonel or the civilian equivalent. Activities may request a waiver to this regulation by providing justification that includes a full analysis of the expected benefits and must include formal review by the activity's senior legal officer. All waiver requests will be endorsed by the commander or senior leader of the requesting activity and forwarded through their higher headquarters to the proponent. Refer to AR 25–30 for specific requirements.

Army internal control process. This regulation contains internal control provisions in accordance with AR 11–2 and identifies key internal controls that must be evaluated (see appendix B).

Suggested improvements. Users are invited to send comments and suggested improvements on DA FormDA FormDepartment of the Army form 2028 (Recommended Changes to Publications and Blank Forms) directly to the Assistant Secretary of the Army (Acquisition, Logistics and Technology) (SAAL–ZF) via email to usarmy.pentagon.hqda-asa-alt.mbx.asa-alt-publication-updates@army.mil.

Distribution. This publication is available in electronic media only and is intended for the Regular Army, Army National Guard/Army National Guard of the United States, and the U.S. Army Reserve.

*This regulation supersedes AR 702–19, dated 12 February 2020.

AR 702–19 • 25 March 2024

UNCLASSIFIED

Administrative and logistics downtime Time associated with processes or tasks not directly involved in restoration or repair activities, such as processing of requests, short-term non-availability of repair facilities, or delays due to establishment of higher priorities.

Built-in test An integral capability of the mission equipment which provides an on-board, automated test capability, consisting of software or hardware (or both) components, to detect, diagnose, or isolate product (system) failures. The fault detection and, possibly, isolation capability is used for periodic or continuous monitoring of a system's operational health, and for observation and, possibly, diagnosis as a prelude to mainte- nance action.

Commercial off-the-shelf Systems or equipment in which the military operating environment is essentially the same as that to which the system was designed and utilized in the commercial marketplace, that is, construction, firefighting, power tools, and so forth, and which does not undergo any significant modification for government usage.

Concept of employment The CONEMP (formerly System OMS/MP) establishes system operational tasks, conditions, standards, future operating environment, and operational attributes that are strategy- and threat-driven, concept- and evidence-based, priority-focused, and data-enabled. They describe how the system is used in Joint oper- ations, as well as Joint and Army system dependencies and interdependencies.

Concept of operations The CONOP (formerly Formation OMS/MP) provides a detailed operational understanding of expected peacetime/wartime usage and requirements expressed in a structured and quantitative format.

Corrective action A documented design, process, procedure, or materials change implemented and validated to correct the cause of failure or design deficiency.

Corrective maintenance All actions performed as a result of failure, to restore an item to a specified condition. Corrective mainte- nance can include any or all of the following steps: localization, isolation, disassembly, interchange, reas- sembly, alignment, and checkout.

Design failure modes and effect analysis The DFMEA is a design risk assessment analysis tool to help evaluate the magnitude of risk relative to a component, subsystem, or system and identify the appropriate design control countermeasure to prevent the occurrence of failure. This measure of risk is identified as a risk priority number and is based on fail- ure severity level, probability of occurrence, and design development phase failure detection activity.

Design for reliability DFR is an engineering process that encompasses tools and procedures to ensure that a product meets its reliability requirements. The reliability requirements should be fully defined and include an item’s func- tion, usage conditions, as well as the tolerated level of risk at specific points in time. The DFR process should be implemented throughout the product life cycle from the design stage through to product dis- posal. DFR will proactively improve product reliability by seeking to minimize weaknesses in design that lead to early failure. DFR is a process that relies on an array of reliability engineering tools with a focus on using the right tool at the right time in the product life cycle.

Developmental item An item of equipment or system not available in the commercial sector and developed by the department with the purpose of providing a new or improved capability in response to a stated need or deficiency.

Downtime The first component is the time waiting for spare parts to arrive via the supply chain, called logistic down- time. The second component is the time to repair, which may consist of maintenance time (that is, MTTR), and in addition, any time that is spent in the queue waiting for the maintenance persons to begin working.

Environmental stress screening Defined as the removal of latent part and manufacturing process defects through application of environ- mental stimuli prior to fielding the equipment. ESS and highly accelerated life testing will be used to en- sure that reliable, available, and maintainable systems are produced and deployed that will be devoid of latent part and manufacturing process defects.

Failure The event, or inoperable state, in which any item or part of an item does not, or would not, perform as previously specified.

Failure mode and effects analysis A procedure by which each potential failure mode in a product (system) is analyzed to determine the re- sults or effects thereof on the product and to classify each potential failure mode according to its severity or risk probability number.

Failure modes, effects, and criticality analysis FMECA extends FMEA by including a criticality analysis, which is used to chart the probability of failure modes against the severity of their consequences. The criticality measure is a function of failure rate, mis- sion time, failure mode apportionment ratio and the failure effect probability. The result highlights failure modes with relatively high probability and severity of consequences, allowing remedial effort to be di- rected where it will produce the greatest value.

Failure rate The total number of failures within an item population, divided by the total time expended by that popula- tion, during a particular measurement interval under stated conditions.

Failure reporting, analysis, and corrective action system A closed-loop system of data collection, analysis, and dissemination to identify and improve design and maintenance procedures.

Fault Immediate cause of failure (for example, maladjustment, misalignment, defect, and so forth).

Maintainability Maintainability is the ability of an item to be retained in, or restored to, a specified condition when mainte- nance is performed by personnel having specified skill levels, using prescribed procedures and re- sources, at each prescribed level of maintenance and repair.

Maintenance ratio A measure of the total maintenance manpower burden required to maintain an item. It is expressed as the cumulative number of man-hours of maintenance expended in direct labor during a given period of the life units divided by the cumulative number of end item life units during the ‘same period.

Materiel availability A M is a measure of the percentage of the total inventory of a system operationally capable (ready for task- ing) of performing an assigned mission at a given time, based on materiel condition. This measure is cal- culated by the materiel developer and can be expressed mathematically as number of operational end items/total population. The A M addresses the total population of end items planned for operational use, including those temporarily in a non-operational status once placed into service (such as for depot-level maintenance). The total life cycle timeframe, from placement into operational service through the planned end of service life, must be included.

Materiel solution Correction of a deficiency, satisfaction of a capability gap, or incorporation of new technology that results in the development, acquisition, procurement, or fielding of a new item, including ships, tanks, self-pro- pelled weapons, aircraft, and so forth, and related software, spares, repair parts, and support equipment, but excluding real property, installations, and utilities, necessary to equip, operate, maintain, and support military activities without disruption as to their application for administrative or combat purposes. In the case of family of systems or systems of systems approaches, an individual materiel solution may not fully satisfy a necessary capability gap on its own.

Materiel system Materiel systems include, but are not limited to, stand-alone or embedded automatic data processing equipment hardware and software; support and ancillary equipment comprising the total materiel system; and multi-Service materiel systems when the Army is lead Service.

Maximum time to repair The maximum time required to complete a specified percentage of all maintenance actions. For example, if a system specification indicated M ax TTR (95 percent) =1 hour, this means that 95 percent of all mainte- nance actions must be completed within 1 hour.

Mean time to repair A basic measure of maintainability. The sum of corrective maintenance times divided by the total number of repairs of the item. The average time it takes to fully repair a failed system. Typically includes fault iso- lation, removal, and replacement of failed item(s) and checkout.

Mission profile A time-phased description of the operational events and environments an item is subject to from the start to the end of a specific mission. Tasks, events, durations, operating conditions, and environmental condi- tions are identified for each mission phase. The mission profiles should state specific quantities of opera- tion (that is, hours, rounds, miles, or cycles) for each mission-essential function within the mission.

Nondevelopmental item An NDI is any previously developed item of supply used exclusively for government purposes by a Fed- eral agency, a State or local government, or a foreign government with which the United States has a mu- tual defense cooperation agreement; any item described above that requires only minor modifications or modifications of the type customarily available in the commercial marketplace in order to meet the re- quirements of the processing department or agency.

Probabilistic requirements A statement of a required probability for performance, for example, reliability: probability of survival until time specified; availability: probability that item is ready when needed; and maintainability: probability that repair completed in time. The designated standard for the chance that a given event will occur.

Reliability Reliability is the probability of an item to perform a required function under stated conditions for a speci- fied period of time.

Reliability critical items list The reliability critical items list provides an itemization of those system hardware/software elements that produce the greatest difference or gap between the allocated reliability requirement and the predicted value. This list provides engineering the ability to focus on design corrective measure efforts to minimize the gap using DFR techniques.

Reliability scorecard The Director, Combat Capabilities Development Command Analysis Center reliability scorecard examines a supplier’s use of reliability best practices, as well as the supplier's planned and completed reliability tasks. The scorecard is important for tracking the achievement of reliability requirements and rating the adequacy of the overall reliability program. An early scorecard assessment may be based solely on a reli- ability program plan, but as time progresses, the scorecard assessment will become more accurate if in- formation from technical interchange meetings, a reliability case, and results from early reliability tests, are included. The reliability case documents the supplier’s understanding of the reliability requirements, the plan to achieve the requirements, and a regularly updated analysis of progress towards meeting the requirements. The reliability scorecard uses eight critical areas to evaluate a given program’s reliability progress: Reliability requirements and planning, training and development, reliability analysis, reliability testing, supply chain management, failure tracking and reporting, verification and validation, and reliability improvements. There are 40 separate elements among the eight categories in the Director, DEVCOM Analysis Center reliability scorecard. Each element within a category can be given a risk rating of high, medium, or low (red, yellow, or green) or not evaluated (gray). The scorecard weights the elements, nor- malizes the scores to a 100-point scale, and calculates an overall program risk score and eight category risk scores.

Reliability, availability, and maintainability program Materiel developers establish system life cycle RAM programs that maximize operational readiness and assure mission accomplishment while minimizing maintenance manpower cost, and logistic support cost. The RAM program designed by the materiel developer for his program will: ensure that materiel systems provided to the Army are operationally ready for use when needed, will successfully perform their as- signed functions, and can be operated, maintained, and sustained within the scope of logistic concepts and policies with skills and training expected to be available to the Army. In short the RAM program is the materiel developer’s plan and process for addressing the CAPDEV’s RAM requirement.

Reliability, availability, and maintainability working group A subgroup of the T&E IPT and established for each Army program with RAM requirements. The RAM working group consists primarily of representatives from the materiel developer, CAPDEV, and the inde- pendent system evaluator. The group may be augmented by others as appropriate. The testers should attend in an advisory capacity.

Repair time The time spent replacing, repairing, or adjusting all items suspected to have been the cause of the mal- function, except those subsequently shown by interim test of the system not to have been the cause.

Root cause analysis Is a method of problem solving to identify the root causes of faults or problems. Focusing correction on root causes has the goal of preventing problem recurrence. The analysis is typically used as a reactive method of identifying event(s) causes, revealing problems and solving them. Analysis is done after an event has occurred. Failure-based RCA is rooted in the practice of failure analysis as employed in engi- neering and maintenance.

System readiness objectives A criterion for assessing the ability of a system to undertake and sustain a specified set of missions at planned peacetime and wartime utilization rates. System readiness measures take explicit account of the effects of RAM, system design, the characteristics and performance of the support system, and the quan- tity and location of support resources. Examples of system readiness measures are combat sortie rate over time, peacetime mission capable rate, A O , and asset ready rate.

Test-analyze-fix-test The process of growing reliability and BIT performance, and testing the system to ensure that corrective actions are effective. Then focus becomes ensuring that the corrective actions are producible and equate to improved RAM in the produced system.