Longevity and expected performance of the existing muon systems at the LHC experiments

Existing muon detectors will face new operating challenges after the HL-LHC upgrade, and various actions are planned to mitigate the expected problems. The main issues are muon chambers reaching rate limits, high occupancy, high dead time, and chambers ageing due to radiation or accumulated charge. It being impossible to rebuild an entire muon system even during a long shutdown, only targeted detector upgrades of specific problematic regions are envisaged. In this talk the main issues related to detector and systems longevity will be covered, and the strategies that the different experiments are planning in order to maintain the performance of their systems at the present level in face of the harsher conditions will be outlined.