DP incident caused by software glitch

Comments from the report:

The two meters move command was given in two one-meter steps to the DP system by the operator with a time lapse of a few seconds. This was investigated by the DP system vendor and was identified as a software glitch. Two consecutive incremental move commands before the window screen has time to refresh resets the DP system to a zero position automatically. Instructions were put in place on-board this and similar vessels until the vendor remedies the software issue.

Considerations of the IMCA Marine DP Committee from the above event:

  • This and similar incidents highlight the need for extensive testing of the software at all stages;
  • Many vendors continuously update their software with patches, revisions, etc. Vessel operators must ensure a robust management of change (MoC) procedure and suppliers should provide an appropriate rigorous testing program;
  • The DP operator(s) appear to have initially responded well to the incident and this is a credit to their training and competence;
  • Reference IMCA documents Guidance for developing and conducting DP annual trials programmes (IMCA M 190) and Guidance on failure modes and effects analysis (FMEA) (IMCA M 166).