Abstract: Based on the conception of the most economical control problem and its limitation for the undefined mathematical models, a new model and definition for the implementation of the optimum or most cost effective ratio of function and quality control over cost control was proposed at the prerequisite satisfying the essential system requirements. The most economical control problems in this field of management system reliability, ABC management method and WSR method, such as the cost of reliability, running cost and the optimal benefits, were explored and studied.

Key words: managerial system, the most economical control problem, reliability, ABC managerial way, WSR way