IntroductionThis dataset contains the frequency and duration that EHV electricity assets are out of service for planned outages from UK Power Networks' Network Vision - an outage planning tracking tool. Which provides a customer facing web portal to provide information about generation customer curtailments and shutdowns to our customers, and provides an interface for our customers to engage with our Outage Planners. We have removed planned outages which are related to customer sites, i.e. this dataset is not the complete view of unplanned EHV network outages. Distributed generation customers should register and login via our Network Vision tool for full visibility.  Methodological Approach Data Extraction and Cleaning: Data is extracted from Network Vision. Data Filtering: We have removed planned outages which are related to customer sites, i.e. this dataset is not the complete view of unplanned EHV network outages. Functional Location Codes (FLOC) Matching: FLOC codes are extracted and matched to Primaries, Grid Sites and Grid Supply Points. Confirmed FLOCs are used to ensure accuracy, with any unmatched sites reviewed by the Open Data Team. Quality Control Statement Quality Control Measures include: Verification steps to match features only with confirmed functional locations. Manual review and correct of data inconsistencies Assurance Statement The Open Data Team and Outage Planning Team worked together to ensure data accuracy and consistency. Other Download dataset information: Metadata (JSON) Definitions of key terms related to this dataset can be found in the Open Data Portal Glossary: https://ukpowernetworks.opendatasoft.com/pages/glossary/