How AIM delivers CNAIM at scale across the distribution network for the UK Electricity Sector.
Client:
UK Electricity DNOs (multiple organisations)
Location:
United Kingdom
Consulting Partner:
Probit
Asset Types:
Electricity substations, transformers, switchgear, overhead lines, poles
AIM Version Used:
AIM 4.0
Key Outcome:
Transparent, scalable CNAIM implementation supporting ED2 & ED3 planning and regulatory submissions across the UK electricity distribution sector
The UK’s Distribution Network Operators (DNOs) are responsible for operating and maintaining over 800,000 km of electricity networks, from urban substations to rural overhead lines.
These regulated businesses operate under Ofgem’s RIIO-ED2 price control framework, which requires them to justify investment through structured, transparent methods.
Since 2017, Ofgem has mandated the use of the Common Network Asset Indices Methodology (CNAIM), a detailed framework for modelling asset risk and health.
CNAIM has been configured in AIM as an industry standard Risk Map template, helping DNOs plan smarter, more efficient investments with full regulatory compliance.
The challenge
CNAIM provides a powerful but complex toolkit for asset risk assessment.
To apply it effectively, DNOs need to ingest and harmonise huge volumes of asset data, run deterministic and probabilistic calculations, and generate clear evidence for regulatory returns.
Many legacy systems struggled with this level of transparency, scalability, or flexibility, particularly as Ofgem’s requirements evolved. The sector needed a flexible, auditable, and high-performance modelling platform that could fully implement CNAIM logic, adapt to network-specific variations, and generate actionable insights for both strategic and tactical investment decisions.
Who worked on this project?
CNAIM has been configured in AIM by Probit as an industry standard Risk Map template, helping DNOs plan smarter, more efficient investments with full regulatory compliance.
How was AIM used?
AIM was configured to act as the central decision-support tool for CNAIM risk modelling and regulatory submission. Core applications included:
- Structured risk mapping – translating health index, criticality, failure probability, and consequence into monetised risk scores.
- Visualisation – creating risk maps and cohort-level views for regulators, investment planners, and asset managers.
- Scenario planning – testing the impact of investment strategies, such as targeted replacement, refurbishment, or do-nothing options, under varying budgets and risk appetites.
- Uncertainty analysis – using AIM’s built-in features to stress-test model assumptions and sensitivity.
- Audit & reporting – producing evidence for Ofgem submissions and internal decision logs using AIM’s transparent reporting and export tools.
Each deployment give DNOs a repeatable, high-trust way to meet their licence conditions while embedding smarter planning capability internally.
The results
AIM CNAIM can deliver major operational and strategic benefits for DNOs across the UK:
- Full compliance with Ofgem’s CNAIM licence conditions.
- More accurate investment targeting, reducing unnecessary expenditure while meeting reliability and safety standards.
- Faster regulatory reporting, with submission-ready outputs generated in minutes.
- Enhanced planning maturity, with wider internal adoption and clearer stakeholder communications.
- Improved integration of CNAIM with wider investment and risk frameworks, including scenario testing for ED2 & ED3 business planning.
Dr Phil Jonkergouw
Managing Director, Probit
Technical insight
AIM’s CNAIM implementation is underpinned by a highly structured, transparent model configuration. Health and criticality scores are calculated using condition data, operational history, and asset metadata, then combined with consequence weightings to generate monetised risk.
AIM supports both CNAIM v1.1 and v2.1 standards, and allows DNOs to customise or override parameters to reflect local network characteristics.
The platform includes standardised reporting templates for annual regulatory returns and interfaces with internal systems via AIM’s API, making it a scalable foundation for long-term risk-based planning.
What comes next for AIM in the Electricity sector?
As the sector moves toward Net Zero and considers the role of digital twins and predictive asset modelling, AIM is positioned to play a wider role in electricity network planning.
The platform’s flexibility ensures it can evolve alongside regulatory frameworks and business strategies, delivering value long after initial deployment.
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