A round robin exercise (RRE) on Improving the Robustness Assessments Methodologies for Structures Impacted by Missiles (IRIS-2012) was instituted jointly by IRSN, France and CNSC, Canada based on experiments conducted by VTT, Finland. The Outcome of the RRE (1st phase) completed in 2010 was not encouraging. The RRE (2nd phase) was floated again in the year 2012 to improve the simulation results close to the experiments. This is the final report associated with that effort.