The processes of managing engineering changes made to electronic instrumentation products allow enterprises to manage the functional parameters, quality and competitiveness of products on the market in small-scale and piecescale production. However, this requires the development of tools for managing engineering changes, adequate models of interaction between executive departments in the development and implementation of design and technological changes in devices. Results of experimental studies of the processes of development, coordination and implementation of engineering changes with the subsequent optimization of standard routes for their processing by divisions and services of the enterprise, which contributed to reducing time costs and simplifying functional relationships between contractors, are presented. A classifier of the causes of engineering changes is developed, changes are grouped according to the complexity of their implementation, and labor intensity of processing notifications by contractors are determined as a criterion for optimizing their service routes. A role model of change management is developed, which highlights the role of the change administrator as the main coordinator of communications and control over the implementation of engineering changes in electronic devices. The model allows for documenting the processes of design, approval, and implementation of engineering changes at the enterprise and organizing information flows between services.