MaxiPark is built on reliable industrial technology. The Real time control is done by the Master-HUB, which is PLC based (as well as the Hubs) with MTBF >20 years. The server is used for what it is good at. See appendix. If the server is down the system runs anyway and no data is lost if the server starts up within approx. a week. If the Master Hub is not working (unlikely) then the Hubs take over in their zones. Guidance is still working on the level described in the specification. Event data is not lost as the server then communicates directly with the Hubs. If a Hub is not working (unlikely) then the sensor and LED takes over the local display and shows occupied and free slot with RED/Green (or Blue for handicap). All errors are immediately automatically reported upwards and the maintenance organization will get the information for countermeasures