Question 1

Who must witness an FMEA Proving Trial for it to be valid for class certification?

Accepted Answer

A surveyor from the relevant classification society must be present to witness and record the trial — self-certification by the operator is not sufficient for class-required FMEA proving FMEA proving trials are a class certification requirement. The classification society requires a surveyor to witness the trials to confirm that the failure modes actually behave as the FMEA predicts, and to verify the trial was conducted correctly. The surveyor's witnessing is what gives the FMEA document its class status.

Question 2

What is the purpose of a Failure Mode and Effects Analysis (FMEA) for a DP vessel, and who mandates it?

Accepted Answer

The FMEA is a class-required document that systematically analyses each identifiable failure within the DP system and proves, by showing which failures are tolerable without loss of position, that the vessel has the redundancy claimed for its class notation Classification societies (DNV, Lloyd's, Bureau Veritas, etc.) require an approved FMEA as part of the DP class notation process. It is the engineering document that demonstrates the redundancy architecture actually delivers what the class notation claims — for DP2, for example, proving that any single failure leaves sufficient redundant systems to maintain position.

Question 3

Who is responsible for commissioning a DP FMEA, and who approves it?

Accepted Answer

The shipowner/operator commissions the FMEA, prepared by a specialist firm; it is reviewed and approved by the classification society as part of DP class certification An FMEA is a specialist engineering document, typically prepared by the DP system manufacturer, a marine engineering consultancy, or the vessel's designers. It must be reviewed and stamped by the classification society before it forms part of the vessel's class certification. It is not a document the DPO or vessel crew can prepare themselves.