The Single Electricity Market Committee (SEMC) decision SEM-15-071 “Process for the Calculation of Outturn Availability” was published on 29 September 2015. The decision applies to both transmission and distribution connected Centrally Dispatched Generating Units (CDGUs) and Controllable Power Park Modules (PPMs) (SEM Dispatchable and Controllable Generation Units) which are disconnected as a direct result of a transmission outage scheduled by the TSO. Outages on the distribution system are not related to the decision paper. This Ex-Post Outturn Availability Connection Asset (OACA) Maintenance Report contains details of the maintenance of OACAs for the 2023 outage season, in accordance with the SEMC decision.