RAMS analysis of the ERIS AO Module and lesson learned before commissioning

ERIS is a new instrument currently under commissioning at Cassegrain focus of ESO VLT UT4.1 Its mission is to replace the NAOS-CONICA and SINFONI instruments to push to the edge the capabilities of this 8-meter class telescope thanks to his AO module by take full advantage of the new DSM (Deformable Secondary Mirror) and the artificial star builder facility (4LGSF - 4 Laser Guide Star Facility).2 The AO module have been built trying to maximize the lifetime and reliability and to minimize the downtime. In this paper we will present the constraint we were subjected and the approach we followed to perform the RAM (Reliability, Availability, Maintainability) analysis, comparing with what we experienced up to now and the lesson learned after the assembly and integration (AIV) process.