Reliability & Maintainability (R&M) Engineering
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:
- Providing adequate R&M staffing.
- Ensuring R&M engineering is fully integrated into SE activities, Integrated Product Teams and other stakeholder organizations (i.e., Logistics, Test & Evaluation (T&E), and System Safety).
- Ensuring specifications contain realistic quantitative R&M requirements traceable to the Initial Capabilities Document (ICD), Capability Development Document (CDD) and Capability Production Document (CPD).
- Ensuring that R&M engineering activities and deliverables in the Request for Proposal (RFP) are appropriate for the program phase and product type.
- Ensuring that R&M Data Item Descriptions (DIDs) that will be placed on contract are appropriately tailored (see the Guidance for Tailoring R&M Engineering Data on the DASD(SE) website).
- Integrating R&M engineering activities and reliability growth planning curve(s) in the Systems Engineering Plan (SEP) at Milestones A and B and at the Development RFP Release Decision Point.
- Planning verification methods for each R&M requirement.
- Ensuring the verification methods for each R&M requirement are described in the Test and Evaluation Master Plan (TEMP), along with a reliability growth planning curve beginning at Milestone B.
- Planning for system and system element reliability growth (i.e. Highly Accelerated Life Test, Accelerated Life Test or conventional reliability growth tests for newly developed equipment).
- Ensuring data from R&M analyses, demonstrations and tests are properly used to influence life-cycle product support planning, availability assessments, cost estimating and other related program analyses.
- Identifying and tracking R&M risks and Technical Performance Measures.
- Assessing R&M status during program technical reviews.
- Including consideration of R&M in all configuration changes and trade-off analyses.
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:
- 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
- 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:
- Block diagrams and modeling
- Failure Mode, Effects and Criticality Analysis (FMECA)
- Subsystem and system-level reliability growth planning activities
- R&M tests and demonstrations
- 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
Statutes, Regulations, Guidance
- DoDI 5000.02, E3: 12. Reliability and Maintainability (R&M)
- DoDI 5000.02, E5: 6.c. OT&E for Reliability and Maintainability
- DoDI 5000.02, E6: 2.a.(1)(a)3. Reliability improvement program
- DAG, Chapter 3-4.3.19 Reliability and Maintainability Engineering
Reliability and Maintainability (R&M) Engineering
DAU Training Courses
- ENG 201: Applied Systems Engineering in Defense Acquisition, Part I - Lesson 2.3
- CLE 301: Reliability and Maintainability
- CLL 030: Reliability Centered Maintenance (RCM)
- LOG 103: Reliability, Availability, and Maintainability (RAM)
- AMSAA Reliability Scorecard
- Exponential Reliability Plot Simulation
- Failure Mode Effects Analysis Tools
- US Army Materiel Command Logistics Support Activity (LOGSA) Tools Suite
Products and Tasks
|10-19-1: R&M requirements, technical planning and technical management are documented in program acquisition documentation.||
|10-19-2: R&M engineering analysis results and technical data are applied to achieve desired system performance.||
|10-19-3: Provide R&M evaluations and recommendations as inputs to product support analysis and testing.||
|10-19-4: Documentation of reliability and maintainability growth and testing.||
Source: AWQI eWorkbook