The method of solving static problems of nonlinear deformation, buckling, and postbuckling behavior of thin elastic inhomogeneous shells is based on the geometrically nonlinear equations of the 3D thermoelasticity theory and use of the moment finite-element scheme. A unified model has been created based on the universal spatial finite element with additional variable parameters. The model considers the multilayer structure of a material and geometrical features of structural elements of an inhomogeneous shell: casing of varying thickness, ribs, cover plates, cavities, channels, holes and sharp bends of the mid-surface. In a number of the authors’ works the reliability of linear and nonlinear solutions for a wide class of inhomogeneous shells has been numerically justified by analyzing their convergence and comparing them with those obtained by other authors. This paper is devoted to the comparative analysis of finite-element models and results of calculation of thin elastic shells using the moment finite-element scheme, and LIRA and SCAD program complexes. The effect of different types of weakening on nonlinear deformation and buckling of shells was studied on the example of isotropic panels under uniform pressure.