Reviewing and updating our methodology into the future
The methodology, in addition to being a licence obligation, also forms part of National Grid’s ISO55001 accredited Asset Management Strategy and Objectives (AMSO). The AMSO includes processes for:
performance evaluation, including asset performance and health monitoring
improvement, including management review, audit and assurance.
AMSO annual monitoring will be used as a basis to review the methodology, in addition to the annual review requirement specified in the RIIO-2 licence. The key parameters used in the methodology – such as predicted rates of deterioration, costs of interventions and maintenance – will be maintained and reviewed through these mechanisms.
As per licence requirements, we will continue to review the methodology on an annual basis at least. Actual modifications to the data and assumptions contained within the methodology will be made if we believe this would drive an improvement in the quantification of the asset risks and improve its decision-making processes. We will always consult on more major changes to our methodology and proposals will be submitted to Ofgem for approval.