Knowledge, capabilities and practices used to design flight, ground support, and facility systems, equipment and instruments for performing their intended function for a specified interval under stated conditions (reliability) and/or have a defined capability to be restored to operational status following a failure (maintainability). Capabilities include the capacity to: define mission success criteria; define and evaluate compliance with systems/equipment reliability/maintainability requirements, including redundancy requirements; model systems/equipment from a reliability/maintainability perspective, including allocations and predictions; perform and evaluate quantitative and qualitative analyses and assessments, including failure modes and effects analyses/critical items list, probabilistic risk assessments, limited life items, quantitative computations; perform and evaluate statistical analysis, trending, and trade-offs; perform and evaluate maintenance analyses, such as reliability centered maintenance techniques; plan, perform and evaluate laboratory testing and engineering analyses; evaluate system/equipment failures to determine root cause and develop corrective actions to prevent similar failures in the future; integrate reliability/maintainability requirements, activities and results with other related disciplines (competencies) such as Safety Engineering and Assurance, Risk Management, Quality Engineering and Assurance, Human Factors, Software Assurance, Acquisition and Contract Management, and Logistics. Also includes availability which can combine the elements of reliability and maintainability in a single parameter."