The choice of the gating feeding system of castings is made by trial and inevitable errors, which are the less, the more experience of the casting engineer who develops the type of system for different types of casting. The design of the gating system and the modeling of the casting process, the formation of casting, and the analysis of emerging defects can be made more efficiently due to the great possibilities of the computer simulation program “Polygon”. Considering the investment casting, the automated design program greatly simplifies the process of finding the best solution, as the investment casting is a complicated and a multiphase process, which requires taking many steps such as designing a press mold, building a cluster, et cetera. The factory design of the casting model is a stock of unified exemplary segments, which are interconnected and characterized by an unproductive usage of a top part. It is proposed to improve the model casting unit “Flange” of the current production, without changing the design of the model units, and increasing the number of models of the casting from one to four, which can lead to an increase in the yield of fit. In preparation for the calculation, the three-dimensional model was divided into a finite element mesh. The computer program calculates the process of solidification and formation of shrinkage defects for metal. The conducted computer experiment showed that this technology of casting arrangement, developed with the aid of the automated design program, can be used in production, which will significantly accelerate the implementation of the annual program, ensuring the production of high-quality castings, which is confirmed by the experimental fills. Programming processing in SprutCAM allowed to reduce processing time by minimizing idling and to obtain a trouble-free control program for the CNC machine.