USAF ILA Handbook - ACC Practice Center - Defense Acquisition ...

B. Relationship between Reliability, Availability
and Maintainability, and Supportability
(RAMS)
B.1 Sustainment quality is driven by performance in RAMS. The PM should establish RAMS
objectives early in the acquisition cycle (certain logistics RAMS criteria should be inserted as
Key Performance Parameters (KPPs) in order to deliver sound weapons systems from a
sustainment perspective) and address them as a design parameter throughout the acquisition
process. The PM develops RAMS system support requirements based on the Initial Capabilities
Document (ICD) or Capability Development Document (CDD) and TOC considerations and
states them in quantifiable, operational terms measurable during Test and Evaluation (T&E).
RAMS system requirements impact total life-cycle cost and all sustainment elements. These
performance requirements are derived from and support the user’s system readiness objectives
and are validated through the RAMS rationale process identified in AFI 10-602, Determining
Mission Capability and Supportability Requirements.
B.2 Application of RAMS and producibility activities during design, development, and
sustainment is guided by a concise understanding of the concept of operations, mission profiles
(functional and environmental), and desired capabilities. It is important to understand rationale
behind RAMS and producibility activities and performance priorities. In turn, this rationale
paves the way for decisions about necessary trade studies among system performance,
availability, and system cost, with impact on the cost effectiveness of system operation,
maintenance, and logistics support. The PM should use Modeling and Simulation (M&S) to
demonstrate RAMS requirements, wherever appropriate to increase confidence in meeting
RAMS requirements, reduce design risk, and possibly reduce overall program, including test,
costs.
B.3 The components of system Availability are a function of Reliability, Maintainability and
Supportability (RMS) and Producibility. There are a number of useful references for these terms
to include, the OSD guide Designing and Assessing Supportability in DoD Weapon Systems: A
Guide to Increased Reliability and Reduced Logistics Footprint; AFI 63-107, Integrated Product
Support Planning and Assessment; AFI 10-602, Determining Mission Capability and
Supportability Requirements; and, DoD 3235.1-H, Department of Defense Test and Evaluation
of System Reliability Availability and Maintainability -- A Primer. However, for the purposes of
this handbook, the following definitions and information in Table B-1 are provided to illustrate
the inter-relationship between these components and sustainment for consideration in conducting
ILAs.
• Reliability: The ability of a system to perform as designed in an operational
environment over time without failure. Reliability requirements address mission
reliability and logistics reliability. The former addresses the probability of carrying
out a mission without a mission-critical failure. The latter is the probability of a
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Air Force Independent Logistics Assessment Handbook