Journal of Information & Systems Management Anatoly Grigorevich Korobeynikov, Michael Evgenievich Fedosovsky, Olga Vadimovna Baranova Andrey Vladimirovich Gurjanov, Igor Olegovich Zharinov, Anatoly Vladimirovich Shukalov 8 2 2018 https://doi.org/10.6025/jism/2018/8/2/45-54 http://www.dline.info/jism/fulltext/v8n2/jismv8n2_1.pdf Background/Objectives: Today much attention is paid to the investigations in the sphere of computer-aided design (CAD), as the automation of difficult technical complexes (DTC) helps improve efficiency, quality and reliability. Methods: Over the recent years a great number of CAD methods other than classical have been developed. They become more complex and formalized; their implementation is associated with a large number of calculations; they are characterized by invariance in terms of the complexity of the designed system, etc. However, it has to be noted that modern requirements to DTC operations have set principally new problems that have to be solved in the process of DTC design. Thereat, to meet these requirements, it is often necessary to stand back from the classical principles of DTC design that have been formulated over half a century ago. In this context there is a great interest in applying the DTC development technologies that would help meet the set requirements. Findings: Founded on the category theory, this study suggests an approach to representing different-type DTC development technologies in a unified form convenient for their integration and coordination within the framework of DTC CAD cycle. Universal theoretical-categorical semantic mathematical models of those technologies have been suggested. According to the category theory, the systemic units (components, subsystems, systems, etc.) are the objects of the relevant categories; the operations are morphisms, the complex technological procedures are diagram structures. In the course of establishing structural alignment of different-type procedures that are predetermined within different categories the relevant functors of the categories have to be determined. Thus, the construct of the category theory enables clear and compact formalization of DTC CAD task. Applications/Improvements: The materials of the study are of practical value for the specialists engaged in solving DTC CAD tasks.