MNT.3:5 - Archetypal Grounding

In the constructed PS17 case, the available specialist interpretation and comparable condition history support recommending bearing replacement at a suitable outage. They do not establish why the degradation arose or whether a recurring programme-level defect has been eliminated.

The planner can therefore give the recommendation now. If the selected intervention exposes material damage, the team preserves the observations needed for the relevant later cause question. It does not claim a lubrication cause merely because the bearing is replaced.

The 48-pump example exposes a different error. Group A has four relevant failure events in 20,000 operating hours; group B has six in 56,000. The comparable crude event rates are 0.20 and approximately 0.107 per 1,000 hours. The first group has fewer events but a higher exposure-adjusted rate. Neither comparison proves a causal policy difference: operating conditions, component histories, event coding and selection may differ.

If two of the six records are preventive removals, even that crude rate needs correction before use. The useful result is a qualified failure account and the event-coding error, not an automatically fitted lifetime distribution.