Purists among reliability professionals are sometimes
concerned about the accuracy of the measurement of the
mean-time-between-failure (MTBF) of an asset. There are many
ways to conduct this failure frequency rate assessment.
Fig. 1 represents a multi-site major refining company. This figure
demonstrates that the corporate reliability engineers are
making reasonably accurate affiliate-to-affiliate comparisons.
However, some petrochemical and refining companies make a
distinction between repairs and failures. As one engineer
wrote, I have a philosophical question around the
classification of repairs vs. failures when tracking rotating
equipment reliability. As I see it, there are
basically two structures or philosophies: asset or
1. Repair frequency and MTBF
tracked by a major corporation with
over 15,000 process pumps.