Systems and constituents, considered collectively, separately and in relation to each other, shall be designed in such a way that an inverse relationship exists between the probability that any failure can result in a total system failure and the severity of its effect on the safety of services.
Maidir le córais agus le comhdhamhnaí, arna mbreithniú i dteannta a chéile, ar leithligh agus ag féachaint don ghaol atá eatarthu, déanfar iad a dhearadh sa chaoi go mbeidh gaol inbhéartach ann idir an dóchúlacht gur cliseadh ar an gcóras iomlán a d'fhéadfadh a bheith mar thoradh ar aon chliseadh agus déine a éifeachta ar shábháilteacht na seirbhísí.