The knowledge of existing casting parameters like casting speed, casting temperature of steel or the H/D ingot ratio is the main precondition to minimize the well-known defects of steel ingots. Especially in demanding metallurgical conditions, it is appropriate to apply the method of numerical modelling using some of the available simulation software. Within the project named the Regional Materials Science and Technology Centre, the technical background of the Department of Metallurgy and Department of Physical Chemistry and Theory of Technological Processes at the Faculty of Metallurgy and Materials Engineering (FMME) VSB - Technical University of Ostrava was extended by the workplace "Laboratory of Modelling of Processes in the Liquid and Solid Phases". The laboratory is equipped by new commercial simulation software intended for 3D numerical simulation of molten steel flow during the filling of a metal mould and the subsequent steel solidification with the prediction of macrosegregation and residual stress leading to cracks. A correct parameter setting of calculation, from the preparation of geometry until the input values of heat transfer coefficients, material properties or the definition of filling time, is a necessary condition for obtaining relevant results from numerical modelling. The paper deals with testing and optimizing the conditions of numerical model settings for simulation of steel ingot casting and solidification in an environment of newly acquired commercial simulation software ProCAST. The conclusion summarizes the obtained knowledge and listed the fields of research, which should contribute to deepening the long-term beneficial cooperation between the commercial sphere and FMME.