1) There may not be a single condition indicator – risk factor
– that authentically tracks the resistance-to-failure curve;
and
2) The resistance-to-failure curve may not be available.
However even with these limitations, we may have an
abundance of condition monitoring information available or may
be capable of gathering a sufficient amount of condition
monitoring data. Where condition monitoring data is available
or capable of being obtained, it is possible to overcome these
limitations.