Finite element modeling (FEM) is highly dependent on the reliability and the accuracy of the input data. The assigned Poisson's ratio is very dominant for the shear strength parameters in the case of the elastic and Mohr-Coulomb (MC) soil model. This value may vary between 0.25 and 0.45 (from gravel to clay). Using FEM analysis with MC soil model, the calculated deformations obtained from the model are not realistic, meanwhile it is perfectly suitable for stability calculations. More accurate displacement results can be obtained with the same software applying Hardening Soil (HS) model. In this case, additional factors are required for the model, such as unloading-reloading modulus of elasticity (Eur), and Over-Consolidated Ratio (OCR). The HS model is useable with dense and hard soils. The soil will behave 3–5 times “stiffer” in unloading-reloading, which defines the choice of the value of the Eur. The above-mentioned factors are important in determining the behavior of soils, especially at the reactions of retaining structures and deformations. The influence of factors is illustrated by a trusted, embedded retaining structure. This study draws attention to the importance of parameter analysis.