Why is it said that planning is a prerequisite for controlling?

Planning and controlling are inseparable twins of management. A system of control presupposes the existence of certain standards. These standards of performance which serve as the basis of controlling are provided by planning. Planning is clearly a prerequisite for controlling. Controlling is blind without planning. If the standards are not set in advance, managers have nothing to control. When there is no plan, there is no basis of controlling. It is utterly inappropriate to think that controlling could be accomplished without planning. Without planning there is no predetermined understanding of the desired performance.