Decision making is an important aspect of planning.  Planning has primacy in the functions of management: planning, organizing, staffing, leading and controlling.  All these are activities of Production, Marketing, Finance, Human Resource Management, Purchasing and Innovation which are activities in management.  Decisions are unique in the sense that there must be courses of action to select from.  Moreover, decisions are of three types namely those under certainty; uncertainty and risk.  In certainty, the decision maker is sure of the inputs and the outcomes and so such statistical tools like expectation would be used.  In uncertainty, you are sure of the inputs, but not the outcomes but there are methods to be used handle the problem.  In the case of risk, there is a probability that what the decision maker is setting out as the expected outputs may not exactly come true due to unforeseeable circumstances but there are measures like standard deviation and variance that could be used to estimate the risk.  No wonder in the paper in which the objective is to do a theoretical review of decision theory some few quantitative examples are to be handled.