Impact of Front-End Maintenance/Upgrades on ALMA Operation

The ALMA Front-End (FE) can host up to 10 receivers, cooled down in the same cryostat and operated through common electronics, the ALMA FE is therefore a single point of failure for an ALMA antenna element (AE). We have in total 66 AEs and 70 FEs: only 4 spares are available in the FE lab to compensate not only for individual FE problems but also for more critical, larger scale issues that can potentially affect simultaneously more than 4 units. FE maintenance done at the OSF (cryogenics, receivers, IF, M&C, integration, verification,...) has therefore a direct impact on the number of antennas available for science at the AOS. Improving the efficiency of that process would consequently improve the efficiency of ALMA science operations.