Mean Fault Detection Time
expected time needed to detect a fault
Note 1 to entry: The MFDT is the time a) in Figure 5, Figure 6 and Figure 7.
Note 2 to entry: The MFDT is equal to zero for immediately revealed failure; (see Figure 6) generally negligible for
quickly detected failures; (see Figure 6) depending of the test policy for the hidden failures. In this case it may be
the main part of the item down time (see Figure 7).
Note 3 to entry: The MFDT used in this Technical Report should not be mixed-up with the mean fractional dead
time which has the same acronym.
Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global Standards