The regional N – 1 calculation can only replace the national N – 1 calculation, where the single largest gas infrastructure of common interest is of major importance for the gas supply of all Member States concerned according to the joint risk assessment.
Izračun N–1 na regionalni ravni lahko nadomesti izračun N–1 na nacionalni ravni zgolj, če je v skladu s skupno oceno tveganja največja posamezna plinska infrastruktura skupnega interesa zelo pomembna za oskrbo vseh zadevnih držav članic.