In the construction process of heavy machine tools, the application of complex solutions in the field of counteracting the negative effects of deformations of machine bodies is a rarely considered problem, however, considering the dimensions of the machine with the increase in dimensions, the problem is intensified. Weight reduction, increased stiffness, improved vibration damping and minimized temperature impact on the machining process as a response to increasing demands on quality, accuracy and speed of machining while minimizing machine and process costs, pose new challenges for constructors, generating new needs. The article presents novel approach to design and optimisation of bodies of heavy-duty machines. The effect of the carried-out research is the methodology for optimizing the construction form of the bodies of heavy machines using the finite element method and methods based on algorithms of advanced computer optimization methods. The developed methodology is an effective tool supporting the design and construction process of machine tools in the selection of the construction form of heavy-duty bodies. As it has been noticed proposed methodology can scientifically improve the design process of new generations of heavy-duty machines and allows you to create a basis for development smart (intelligent) machine which fulfils the requirements and ideas of Industry 4.0. Without preparation of series of prototypes, it allows to achieve advanced solution with avoided development version errors what leads to resources and founds savings.