Selection scheme

Ships are selected for inspection based on a calculation of the history of inspection and generic factors (such as age, shiptype, Ship risk type etc.). Each aspect of the history and generic factors is weighed and the outcome is a priority indication.

Periodic Inspections are carried out at intervals that are determined by the Ship Risk Profile.
Ships become due for a periodic inspection in the following time windows:

  • For High Risk Ships – between 5-6 months after the last inspection in the Paris MoU region.
  • For Standard Risk Ships – between 10-12 months after the last inspection in the Paris MoU region.
  • For Low Risk Ships – between 24-36 months after the last inspection in the Paris MoU region.

Additional Inspections are triggered by overriding or unexpected factors.

Periodic Inspections and Additional Inspections count equally. Therefor the time span for the next periodic inspection re-starts after each inspection

Overriding Factors

The overriding factors are considered sufficiently serious to trigger an additional inspection at Priority I.

Unexpected Factors

Unexpected factors could indicate a serious threat to the safety of the ship and the crew or to the environment, in such a case the need to undertake an additional inspection is for the professional judgement of the Authority.

You can read more on Overriding and Unexpected Factors by clicking on the link below.


The selection scheme is divided into two priorities:

  • Priority I: ships must be inspected because either the time window has closed or there is an overriding factor.
  • Priority II: ships may be inspected because they are within the time window or the port State considers an unexpected factor warrants an inspection.

The priority and the level of selection will be shown for each ship in the information system.

If you want to know more about the Selection Scheme, you can read Annex 8 of the Paris MoU Memorandum text.