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The finite element model of a general viscoelastic rotor-shaft supported by journal bearings becomes bulky and complicated. Higher order model is derived after incorporating operator based constitutive relationship for damped shaft. Due to consideration of internal damping, gyroscopic effect and journal bearing asymmetry is also present in the higher order system (Roy and Chandraker (2017))1. Hence, the system becomes computationally stiff, especially for eigen analysis. Thus it becomes necessary to reduce the size of the model with important coordinates for better computational efficiency and to make the eigenvalue analysis easy. The interest of the paper is to investigate the effectiveness of a Modified System Equivalent Reduction Expansion Process (SEREP) as a tool to reduce higher order system equations of motion. The reduction process is done on equations of motion written in state-space form. The conventional SEREP process uses only the right eigenvectors whereas the modified SEREP uses both right and left eigenvectors to form the transformation matrix (Das and Dutt (2008))2. The equation of motion in state space for full model and reduced model are written in Eq. (1) and Eq. (2) respectively. A multi disc - rotor - shaft – bearing system is considered for numerical illustration to show the effectiveness of the process. The effectiveness of the reduced model is examined using various dynamic parameters. Fig. (1) and Fig. (2) show the Campbell diagram for full and reduced model respectively.