This enable the decision maker to select the most appropriate course of action. This needs more care and efforts. If validates or verifies the expected outcomes of each hypothesis. Here greatest volume and intensity of data are likely to be gathered. Sometimes uncertain conditions may force the decision maker to use his intuition and judgment but in general major decisions are always based on convulsive research.

The utility and performance of decision with regard to the solution of a problem can be ascertained by means of performance monitoring research. It reports the changes in operational results that appears appropriate to the action and also ascertains whether the conditions under which the action was taken have turned out to be significantly differently from those when the action was selected.