Influence functions and their graphical representation – influence lines are used in calculation of structures exposed to moving loads. They are used to determine the position of the moving load that will give the most adverse impacts of construction or its components (maximum internal forces, deflections and displacements) and to determine the values of these quantities. The aim of this work is to analyze influence lines of particular statically determined system obtained by software, and compare them with the same obtained by analytic methods. Although computers have become an indispensable tool in engineering practice, it is necessary to accepted numerical results obtained by various applications with exceptional caution, and also study the possible limitations of some software. On examples are studied influence lines obtained software package Autodesk Robot Structural Analyses and compared with the analytic results. It is observed a good correlation of results and the resulting operating errors can be generalized and corrected by the input parameters of the program, so the results can be used for static analysis of structures.