The purpose of this work is a comparison of pension systems of the selected countries?the pension systems and reforms of Austria, the Czech Republic, Slovakia, Sweden, Poland, and Chile will be our subjects of interest. Firstly, we focus on a short historical overview of the development and classification of pension systems in general. Consequently, the main part of this chapter deals with different scenarios, which should show whether the systems would be stable in the future. For these purposes, we developed utility in Mathematica. We tested normality of salary samples from Slovakia by robust tests for normality and computed pensions in several scenarios.