Technical Services: Unavailability Root Causes, Strategy and Limitations

CERN's technical infrastructure is a common root cause source of unavailability impacting the accelerators, injectors, experiments and the computer center. The Technical Infrastructure Operation Committee (TIOC) monitors, analyses and coordinates the technical infrastructure operation in order to increase the overall availability of the LHC. All events impacting or potentially affecting directly or indirectly the LHC runs are analyzed and recommendations are made for immediate intervention or long term actions. Tools and performance indicators are progressively being implemented considering a more structured approach to system breakdown identification and fault tree analysis. The unavailability caused by the technical infrastructure during 2016 has been analyzed and compared with previous years together with the impact of electrical power glitches. Tools and strategies to perform availability analysis across all systems and equipment are proposed and the tracking of the root cause analysis and dependences assessed to explain past and future performances.