Purpose of research lies in the grounding of the theoretical statements and development of practical recommendations on forming accounting support of the controlling system functioning, which will assist in the improvement of the efficiency and effectiveness of management in the part of working out managerial decisions for reaching the goals set by an enterprise. Object of research: accounting system in the controlling environment. Subject of research: the totality of theoretical and practical grounds of the accounting system functioning as an instrument of the controlling support. Methods of research: historical method, logical analysis, synthesis, induction, deduction, theoretical generalization, grouping, specification, system approach, cause and effect method, modeling, statistical observation, graphic method. Scientific novelty of the results obtained lies in the grounding of the place of accounting system in the controlling environment, working out of the recommendations on improving the accounting support of the controlling system, which will assist in the improvement of the efficiency and effectiveness of management in the part of preparing alternative decisions for reaching the goals set by an enterprise.The main statements of scientific novelty of the results obtained lie in the following: for the first time it has been proved on the basis of the hierarchal multilevel system theory that accounting in the controlling environment has a twofold nature and is considered to be one of the controlling objects, coordination means as well as instrument of its information support, which contributes to the development of theoretical and methodical statements of controlling. Тhe issues have been improved as follows: interpretation of controlling as a system which provides the coordination of information subsystems of company's management system with the purpose of increasing the efficiency and effectiveness of management, which facilitates sorting and development of the economic terminology; theoretical components of the controlling concept (subject, object, purpose and objectives) on the basis of system approach application, which assists in delimitation of its theoretical borders and introduction of controlling into the managerial activity of domestic enterprises; accounting organization in the part of technological constituent (forms and timetable of workflow of internal reporting have been worked out) by the stages of capital circulation (purchase, production, sale) with the purpose of improving information support of business activity management; the procedure of measuring the efficiency of controlling system at an enterprise and controllers work on the basis of applying quantitative indexes (in the light of coefficients of controlling application efficiency, payback period of the controlling system introduction, unit costs incurred for maintaining the controlling department in the total sum of company's administrative expenses, etc.) and qualitative indexes (in the light of information, economic and strategic as well as organizational and managerial features) for making managerial decisions as for the expediency of introducing and implementing controlling at an enterprise; controlling models by the stages of capital circulation (purchase, production, sale) on the basis of the accounting support, which increases the efficiency of making managerial decisions. The following issues undergone further development: periodization of the controlling development in the interconnection with the accounting system on the basis of its application in foreign countries, which enabled to understand the essence of controlling as well as specify its objectives and prerequisites of formation at all development stages; grounding of the requirements to computer information systems and criteria of choosing software under computerization of the controlling system, which enabled to minimize risks while its implementation and provide the coordination of its subsystems. Implementation extent: research results have been implemented into the practice of JSC "Zhytomyr Butter Plant", PLC "Spetsbudmontazh - 503", Utility Company "Uzhgorod Local Printing House", Zhytomyr State Technological University, Transcarpathian State University.
