Question 1

An engineer notices a piece of equipment running with a slightly unusual vibration, not yet at a level that would trigger any alarm or formal defect report, and raises it informally for closer monitoring and an earlier-than-scheduled inspection. The inspection finds early-stage wear that, left unaddressed, would likely have caused a failure within weeks. How should this be regarded?

Accepted Answer

As a strong example of proactive, anticipatory maintenance practice worth recognising and reinforcing — the engineer noticed a subtle deviation from normal before it reached any formal threshold, and acted on it early, which is exactly the kind of vigilance that prevents an eventual unplanned failure rather than just reacting to one This is the Safety-II principle applied directly to maintenance — the value here is entirely in catching a developing problem before it became an unplanned failure, and a purely Safety-I lens (which only logs actual failures and alarms) would never capture or reward this kind of proactive vigilance.

Question 2

What is the core purpose of a vessel's Planned Maintenance System (PMS), beyond simply scheduling tasks?

Accepted Answer

To ensure equipment is maintained at intervals based on manufacturer recommendation, class/statutory requirement, and operational criticality before it fails, shifting maintenance from purely reactive (fix it when it breaks) to proactive — with the added benefit of providing a documented, auditable history of what has been done and when The shift from reactive to proactive maintenance is the entire point — equipment maintained on a planned schedule is far less likely to fail unexpectedly than equipment only attended to after it breaks, which matters enormously for safety-critical systems where an unexpected failure has serious consequences. A PMS never eliminates all breakdown maintenance, but it should substantially reduce it for well-managed critical equipment.

Question 3

Why does a well-designed PMS apply different maintenance rigour and spares-holding policy to different pieces of equipment, rather than treating every item identically?

Accepted Answer

Equipment is assessed for criticality based on the consequence of its failure (safety, environmental, or operational impact) and how quickly that consequence would materialise — safety-critical equipment with no redundancy (e.g. steering gear) warrants tighter maintenance intervals and guaranteed spares availability compared to equipment whose failure has minimal or easily-managed consequence This mirrors the FMEA/WCF logic seen in the DP content directly — not all equipment failures carry equal consequence, and a PMS that does not differentiate is either over-maintaining low-consequence equipment (wasting resource) or under-maintaining high-consequence equipment (real risk), neither of which is good resource allocation.