This document discusses the controlling function of management. It defines controlling as verifying that plans, instructions, and principles are being followed and that resources are being efficiently utilized to achieve goals. Controlling measures deviations from standards, identifies causes, and enables corrective actions. The key steps of controlling are establishing standards, measuring performance, comparing to standards, and taking corrective actions. Controlling is an end function, pervasive, forward-looking, dynamic, and related to planning. Planning precedes controlling, and they work together in a systems approach with planning leading to results which are then corrected through controlling actions.