SUMMARY
The subject matter of the article is the impact of the sequence of changes for auxiliary time spent on idle motions of a machine unit when changing a machinable area or when changing tools. The goal of the study is to improve the finishing milling capacity when machining geometrically complicated parts by minimizing auxiliary time, which enables determining the optimal sequence of changes. The following tasks were solved in the article: the main approaches to developing general strategies for machining geometrically complicated parts were determined; algorithmic solutions and methods for determining the best route for moving tools from site to site were analyzed as well as the advantageous sequence of machining geometrically complicated parts, taking into account motion limitations and constraints for tool life; a mathematical model of minimizing idle motions when changing machinable areas and tools on the basis of the point description of the part geometry. The following methods were used: theoretical and experimental research methods including the system and structural analysis; the methods of mathematical statistics; numerical methods of advanced mathematics, the graph theory. The following results were obtained. As a result of complex theoretical and experimental studies, methods for optimizing particular and general strategies when machining geometrically complicated parts were identified; a method for determining the optimal route of cutters of the same size when moving within a group of machinable areas was developed; based on the point description of the part geometry, a mathematical model for minimizing idle motions when changing machinable areas was developed; the parameters that minimize the idle motions when changing machinable areas and provide the implementation of algorithms for calculating the lengths and positions of local clearance plane for sequentially machined sections are determined. Conclusions. The use of approaches to develop common strategies for machining geometrically complicated parts contributes to an increase in the capacity and efficiency of using expensive multi-purpose machines. The use of this method for determining the best route for moving the tools enables determining the route variant with the minimum value of the auxiliary time spent on idle tool motions.