This difference is important in selecting an adequate inventory management approach.
Independent Demand
Independent demand exists where the rate of use for an item does not relate directly to the use of another item (for example, finished goods such as a computer). An inventory of an item is said to be falling into the category of independent demand when the demand for such an item is not dependent upon the demand for another item.
Finished goods Items, which are ordered by External Customers or manufactured for stock and sale, are called independent demand items. Independent demands for inventories are based on confirmed Customer orders, forecasts, estimates and past historical data.
The demand for cutting oil used by the machines on the line cannot be calculated accurately from the production schedule and bills of materials; thus, cutting oil is said to have an independent demand.
Dependent Demand
If the demand for inventory of an item is dependent upon another item, such demands are categorized as dependent demand. Raw materials and component inventories are dependent upon the demand for Finished Goods and hence can be called as Dependent demand inventories.
An item is said to exhibit dependent demand characteristics when its use is directly dependent on the scheduled production of a larger component or parent product of which the item is a part. Hence, in a plant producing automobile engines the demand for engine block casting is a dependent demand; once the production schedule for a group of engines is established, the planner knows with