MAORY/MORFEO: the RAM analysis approach for the preliminary design

Abstract

MORFEO is the Multi-conjugate adaptive Optics Relay For ELT Observations, formerly known as MAORY (Multiconjugate Adaptive Optics RelaY), designed for the ELT first light instrument MICADO. With the goal of being compliant to Reliability, Availability and Maintainability (RAM) requirements, we present the approach for the RAM analysis carried out for MORFEO at system level. RAM analysis allows to monitor the possible failures that could occur at lower levels and to highlight criticalities, hence leading to recommendations for design changes, thus preventing failure propagation at higher levels, and providing a maintenance strategy to keep the system in operation. The RAM process requires not only a series of interactions with all subsystem engineers, but also with AO specialists that identify all possible degraded modes that are a key aspect of failure assessment, but must be driven by requirements on science. The RAM approach we will outline is the base for having a more reliable design and for defining a suitable maintenance plan, with the final goal of enhancing the system availability, thus avoiding critical down time of the instrument during its entire lifetime.