[en] Improvement of beam availability is a prime objective of the present LANSCE (Los Alamos Neutron Scattering Center) Upgrade. A RAMI (reliability, availability, maintainability, and inspectability) program is being developed to identify the most cost-effective improvements to achieve the availability goal. The beam-delivery system is divided into subsystems appropriate for the modeling of availability. The availability of each subsystem is determined from operation data and assessment of individual component designs. These availability data are incorporated in an availability model to predict the benefit of improvement projects to achieve cost-benefit prioritization. Examination of the data also identifies a comprehensive list of factors affecting availability. A good understanding of these factors using root-cause analysis is essential for availability improvement. This paper describes the RAMI program and the development of the availability model