New and expanded passenger rail projects must deliver dependable scheduled service with affordable operations and maintenance (O&M) costs. Reliability, Availability, and Maintainability (RAM) characteristics of equipment, facilities, and rolling stock determine the dependability and O&M costs of a rail system. System designers, builders, and operators can achieve suitable RAM characteristics by applying established engineering concepts, methods, tools, and techniques throughout the system life-cycle. Targeting and achieving system-wide RAM characteristics are necessary to assure the quality of service delivered to the customers and control O&M costs.
A rail project reaps maximum benefits from applying system-wide RAM assurance processes if the RAM activities begin in an early planning phase, whether for a green field or an upgrade project, a single passenger rail system subsystem or a whole new railroad or rail service. Application of RAM assurance processes early on guide design to ensure RAM requirements are met in support of achieving overall service dependability and costs goals. RAM assurance processes are often applied at the railroad subsystem level such as rolling stock, train control, communications, traction power, and even infrastructure and civil works.
Key challenges in the early phases of a project are setting the appropriate system-wide performance indicators and metrics, using on-time performance, O&M cost, and other system-wide indicators; and then apportioning those targets to each railroad subsystem in a suitable metric that is measurable and directly relevant to each subsystem and its provider.
Once the rail system is integrated and in operation, further steps must assure that the system as a whole meets the system-wide RAM targets. This paper describes a model and associated processes that establish the needed parameter sets, analyses, and metrics, and provides a case study based on a new high-speed rail project.