Damped vibro-acoustic problems lead to complex large FE models. A classical way to reduce computationtime is the component mode synthesis method (CMS). In presence of damped materials such as visco- and poro-elastic, the classical decoupled bases used in CMS method have some limitations and can be fulfilled with several residual vectors. Another point that must be addressed in the analysis is the robustness of bases according to structural modifications: when the model has parametric modifications, the same strategy can be applied to define robust bases instead of forming new bases in order to take into account these modifications.This study compares the CMS methods of two formulations-
