The report includes a summary of the test results, tool information, test procedures and the current draft (version 2.4.12) of the ENTSO-E Common Grid Model Exchange Standard (CGMES). The testing identified important issues relating to the CIM standards, to be referred to IEC/WG13 (the working group dealing with CIM standards for grid model exchange) as well as ENTSO-E CGMES related issues (outlined in the report). The majority of the issues identified have now been resolved. ENTSO-E IOP test participants confirmed that the issues identified in the previous IOP test, IOP 2012, are resolved in the new version of the CGMES. The CGMES was amended to include a new approach to exchange input parameters for load flow simulations, HVDC modeling, and dynamics data exchange. Next Steps The test results and the latest post-IOP version of the ENTSO-E CGMES will now be analysed by ENTSO-E. A decision on the approval of the CGMES is expected by end 2013. For further information, please contact Chavdar Ivanov, Ph.D., Research and Development Senior Advisor, ENTSO-E: +32 2 741 09 69 / chavdar.ivanov@entsoe.eu Download the full IOP report, CGMES, annexes and supporting documents at the: CIM for Grid Models – Standards & IOP Tests webpage