Reliability & Maintainability (R&M) Engineering

Overview

The purpose of Reliability and Maintainability (R&M) engineering (Maintainability includes Built-In-Test (BIT)) is to influence system design in order to increase mission capability and availability and decrease logistics burden and cost over a system’s life cycle. Properly planned, R&M engineering reduces cost and schedule risks by preventing or identifying R&M deficiencies early in development. This early action results in increased acquisition efficiency and higher success rates during operational testing, and can even occur in the development process as early as the Engineering and Manufacturing Development (EMD) phase.

Role of the PM and SE

DoDI 5000.02, Enc 3, sec. 12 requires Program Managers (PMs) to implement a comprehensive R&M engineering program as an integral part of the systems engineering (SE) process. The Systems Engineer should understand that R&M parameters have an impact on the system’s performance, availability, logistics supportability, and total ownership cost. To ensure a successful R&M engineering program, the Systems Engineer should as a minimum integrate the following activities across the program’s engineering organization and processes:

As part of the SE process, the R&M engineer should be responsible for the R&M activities by the acquisition phase outlined in Table 48.

Table 48: R&M Activities by Acquisition Phase

During the MSA Phase, the R&M engineer, as part of the program SE team, should:

  • Analyze conceptual design approaches and estimate the feasibility with respect to R&M ICD performance capabilities
  • Perform AoA trade-off studies among R&M, availability and other system performance parameters to arrive at a preferred system alternative. The studies should be performed in conjunction with product support, cost and design personnel, using the DoD RAM-C Rationale Report Manual
  • Conduct a Reliability, Availability, Maintainability and Cost (RAM-C) analysis. For Major Defense Acquisition Programs (MDAP), prepare a preliminary RAM-C Rationale Report and attach the report to the SEP for Milestone A
  • Translate ICD performance capabilities and draft CDD thresholds to R&M specification requirements based on the Concept of Operations/Operational Mode Summary/Mission Profile (CONOPS/OMS/MP), failure definitions and utilization rates
  • Develop a system reliability growth planning curve and include it in the SEP. Reliability growth curves should be stated in a series of intermediate goals and tracked through fully integrated, system-level test and evaluation events until the reliability threshold is achieved. If a single curve is not adequate to describe overall system reliability, curves for critical subsystems, with rationale for their selection, should be provided
  • Use data from the RAM-C Rationale Report to provide the following for logistics design support:
    1. The initial failure mode assessment, including effects of failure on system performance and the probable manner in which each failure mode would be detected to provide guidance to planning and the conceptual design of the diagnostics concept and maturation process
    2. Failure rate and removal rate estimates, for both corrective and preventive maintenance, to provide a realistic basis for equipment and replaceable unit spares provisioning planning
      • Define contractor R&M engineering activities in the RFP and contract Statement of Work for the TMRR phase, which should include:
        1. Allocations
        2. Block diagrams and modeling
        3. Predictions
        4. Failure Mode, Effects and Criticality Analysis (FMECA)
        5. Subsystem and system-level reliability growth planning activities
        6. R&M tests and demonstrations
        7. Failure Reporting, Analysis and Corrective Action System (FRACAS)

During the TMRR phase, the R&M engineer, as part of the program SE team, should:

  • Participate in trade studies during requirements analysis and architecture design
  • Review results of R&M engineering analyses, verification tests, design approach, availability assessments and maintenance concept optimization to verify conformance to requirements, and to identify potential R&M problem areas
  • Contribute to integrated test planning to avoid duplication and afford a more complete utilization of all test data for R&M assessment. Comprehensive test planning should include subsystem reliability growth and maintainability and BIT demonstrations as appropriate
  • Understand schedule and resource constraints, and adjust the reliability growth planning curve based on more mature knowledge points. Include updated reliability growth planning curve in the SEP at the Development RFP Release Decision Point and at Milestone B, and in the TEMP at Milestone B
  • Integrate R&M engineering analyses with logistics design support in the following areas: requirements and functional analysis; test planning; Reliability Centered Maintenance (RCM) and Condition Based Maintenance Plus (CBM+); and refinement of the maintenance concept, including the Level of Repair Analysis (LORA) and maintenance task analysis
  • Verify that plans have been established for the selection and application criteria of parts, materials and processes to limit reliability risks
  • Define contractor R&M engineering activities in the RFP and contract Statement of Work (SOW) for the EMD phase, during which R&M quantitative requirements and verification methods are incorporated
  • Update the RAM-C analysis to support the Development RFP Release Decision Point ensuring the JCIDS Sustainment Thresholds in the CDD are valid and feasible. For MDAPs, attach the updated RAM-C Rationale Report to the SEP for Milestone B

During the EMD phase, the R&M engineer, as part of the program SE team, should:

  • Perform evaluations to assess R&M status and problems
  • Update the RAM-C analysis, ensuring the JCIDS Sustainment Thresholds in the CPD are valid. For MDAPs, attach the updated RAM-C Rationale Report to the SEP for Milestone C.
  • Ensure that the product baseline design and required testing can meet the R&M requirements
  • Ensure the final FMECA identifies failure modes, and their detection methods, that could result in personnel injury and/or mission loss, and ensure they are mitigated in the design
  • Ensure that the detailed R&M prediction to assess system potential to meet design requirements is complete
  • Verify through appropriate subsystem/equipment-level tests the readiness to enter system-level testing at or above the initial reliability established in the reliability growth planning curve in both the SEP and the TEMP
  • Verify system conformance to specified R&M requirements through appropriate demonstration and test
  • Implement a FRACAS to ensure feedback of failure data during test and to apply and track corrective actions
  • Coordinate with the Chief Developmental Tester (T&E Lead) and Operational Test Agencies (OTA) to ensure that the program office and OTA data collection agree on R&M monitoring and failure definitions, and that R&M and BIT scoring processes are consistent in verification of requirements through all levels of testing
  • Define contractor R&M engineering activities in the RFP and contract SOW for the P&D phase to ensure adequate R&M engineering activities take place during P&D and the RFP and contract SOW provide adequate consideration of R&M in re-procurements, spares and repair parts
  • Verify that parts, materials and processes meet system requirements through the use of a management plan detailing reliability risk considerations and evaluation strategies for the intended service life. Include flow of requirements to subcontractors and suppliers. See MIL-STD-1546 (Parts, Materials, and Processes Control Program for Space and Launch Vehicles) and MIL-STD-1547 (Electronic Parts, Materials, and Processes for Space and Launch Vehicles) and MIL-STD-11991 (General Standard for Parts, Materials, and Processes)

During the P&D phase, the R&M engineer, as part of the programs SE team should:

  • Verify initial production control of R&M degradation factors by test and inspection, production data analysis, and supplemental tests
  • Verify R&M characteristics, maintenance concept, repair policies, Government technical evaluation and maintenance procedures by T&E
  • Identify R&M and production-related BIT improvement opportunities via FRACAS and field data assessment
  • Review Engineering Change Proposals (ECP), operational mission/deployment changes and variations for impact on R&M
  • Update R&M predictions and FMECAs based on production tests, demonstration tests, operational evaluation and field results and apply them to the models previously developed to assess impacts on maintenance procedures, spares, manpower, packaging design, test equipment, missions and availability
  • Verify that parts, materials and processes management requirements for limiting reliability risk and "lessons learned" are utilized during all design change efforts including change proposals, variations, substitutions, product improvement efforts or any other hardware change effort

During the O&S phase, the R&M engineer, as part of the program SE team should:

  • Assess operational data to determine the adequacy of R&M and BIT characteristics performance; maintenance planning, features and procedures; provisioning plans, test equipment design; and maintenance training
  • Identify problem areas for correction through ongoing closed-loop FRACAS and field data assessment
  • Monitor availability rates and respond to negative trends and data anomalies

Resources

Statutes, Regulations, Guidance

DASD(SE) Initiative

Reliability and Maintainability (R&M) Engineering

ACQuipedia Articles

DAU Training Courses

DAU Tools

Media

Products and Tasks

Product Tasks
10-19-1: R&M requirements, technical planning and technical management are documented in program acquisition documentation.
  1. Identify where R&M considerations are required in program and acquisition documentation, i.e. SEP, AS, TEMP and LCSP.
  2. Document R&M Engineering in the Systems Engineering Plan (SEP) to define the methods for implementing R&M engineering tasks, technical staffing, and technical management.
  3. Verify that RAM-C Rationale Report results have been incorporated into the JCIDS documents, i.e., CDD and CPD, and then are used to inform the development of specifications.
  4. Develop Technical Performance Measures (TPMs) consistent with the reliability growth planning curve and incorporate into the program’s Systems Engineering Plan (SEP).
  5. Document in program acquisition documentation how the results of a reliability growth assessment support the likelihood of meeting the program requirements threshold.
  6. Verify that program engineering organization charts describe how Reliability & Maintainability (R&M) engineering is integrated into Systems Engineering activities, Integrated Product Teams, and other stakeholder organizations and documented in the Systems Engineering Plan (SEP).
10-19-2: R&M engineering analysis results and technical data are applied to achieve desired system performance.
  1. Develop R&M allocation assignments to system components in order to support attainment of desired system-level performance.
  2. Develop Failure Definitions and Scoring Criteria (FDSC) to score maintenance data, calculate metric values against specification requirements and CDD thresholds, and for use in contractor R&M allocation and prediction reports.
  3. Develop Failure Mode, Effects and Criticality Analysis (FMECA) to assess the severity of the effects of system failure modes on system performance.
  4. Use the results of the contractor’s FRACAS and associated R&M data collection systems to identify and correct problems in equipment design or manufacturing.
  5. Translate JCIDS R&M thresholds to performance specification requirements using Operational Mode Summary/Mission Profile (OMS/MP) and failure definitions.
  6. Conduct trade-off studies among R&M, availability, life cycle cost and other system performance parameters to effectively determine a preferred system solution.
  7. Verify that R&M block diagrams and math models reflect the equipment/system configuration and support the development of R&M allocations and predictions.
  8. Verify that R&M prediction methods, i.e., parts count, stress analyses, physics of failure, and software reliability methods, are appropriately applied to a proposed design or on a comparison of alternative designs.
  9. Verify that results of R&M assessments of existing equipment (i.e., GFE/COTS) and their interfaces are appropriately applied to ensure that the equipment has a proven history of R&M and that the equipment is correctly used in system design.
10-19-3: Provide R&M evaluations and recommendations as inputs to product support analysis and testing.
  1. Identify Reliability & Maintainability (R&M) analysis events, tests and demonstrations required to develop product support plans.
  2. Identify product support problem areas for correction using a closed-loop Failure Reporting, Analysis and Corrective Action System (FRACAS).
  3. Assess the impact Engineering Change Proposals (ECP), operational mission / deployment changes, and other system variations have on R&M and product support.
  4. Assess the results of R&M predictions and Failure Modes, Effects, and Criticality Analyses (FMECAs) and determine how operations are impacted related to spares management, manpower estimates, level of repair analyses, troubleshooting procedure development, and availability calculations.
10-19-4: Documentation of reliability and maintainability growth and testing.
  1. Identify the criteria to evaluate contractor test plans for adequacy and completeness of test plan data to support R&M considerations.
  2. Verify that R&M requirements verification methods are included in the program’s system performance specification and Test and Evaluation Master Plan (TEMP).
  3. Assess that results from reliability growth tests to verify that the system meets technical performance reliability requirements of the specification.
  4. Assess the results of system maintainability and Built-In-Test (BIT) demonstrations to verity that the system meets technical performance maintainability requirements of the specification.
  5. Document the results of the assessment and provide to decision maker.

Source: AWQI eWorkbook

On this page

  1. Overview
  2. Role of the PM and SE
  3. Activities by Acquisition Phase Table
  4. Resources
Back to top