The term cost is made specific when it is modified by such descriptions as direct prime conversion indirect fixed variable controllable product period joint estimated standant sunk or out of pocket. Each modification implies a certain attribute that is important in measuring cost. Each of these cost is recorded and accumulated when management assigns costs to inventories prepares financial statements plans and controls costs makes strategic plans and decisions chooses among alternatives motivates personnel and evaluates performance. The accountant involved in planning and seeksion making must also work with future. Replacement differential and opportunity cost none of which is recorded and recorded and reported in external financial statements.