I propose to the committée Standard Internationàle that they incorporate a new base unit into their system of defined units.
PpA – Problems per Annum
This is a measure how many times a system, model, theory or implementation suffers from problems that requires attention yearly based on a standard calendar year. Where so applicable the year should follow the modified Gregorian calendar and the start of the year is 1/1 00:00 UTC (Universal coordinated time) as per definied by the GPS clock.
In future system specifications I assume that you all will be using the PpA parameter to described anticipated number of breakdowns that requires attention to restore the system to normal function.