Common Network Asset Indices Methodology (CNAIM) models

In Great Britain, the energy regulator Ofgem introduced regulatory reporting requirements for Distribution Network Operators (DNOs) for the 2015-2023 regulatory period (RIIO-ED1) to report information relating to both asset health and criticality. This information is known as the Common Network Asset Indices, and these provide an indication of the risk of condition based failure of network assets.

The requirement for reporting of Network Asset Indices is outlined in the DNOs’ Standard Licence Condition 51. This licence condition also requires DNOs to jointly develop a Common Network Asset Indices Methodology, such that DNOs adopt a common approach to the evaluation of asset health and criticality.  The resulting “Common Network Asset Indices Methodology” covers 25 electrical assets classes including Switchgear, Transformers, Overhead lines and Cables.

EA Technology have been supporting the GB DNOs through the development of their Common Network Asset Indices Methodology. Following the successful approval of the methodology, we worked to implement the methodology with each of the GB DNOs, and to embed it within their organisations.

These models offer

• Off the shelf delivery
• 25 models, compliant with the GB regulator’s standard
• 25 data interfaces
• Data upload via Data Loader software
• SLC51 regulatory compliance with fixed calibration for GB DNOs
• Flexible calibration to enable the methodology to be used by non-GB DNOs

For full details of the methodology, please use the following links:

OFGEM – Decision on DNO Common Network Asset Indices Methodology

OFGEM – DNO Common Network Asset Indices Methodology