effectivenesseffectiveness - A measure of the extent to which a process fulfills its intended purpose.
Illustration: An organization is effective when it produces the right product at the right time in the right quantity. Inventory dollar day (IDD) is a measure of the effectiveness of the production process. The IDD target level is zero. IDD measures "things that should not have been done but nevertheless were". For example, making inventory to keep workers busy when, based on current demand, the workers should have been idle creates inventory dollar days and the production process is ineffective. When an item is made early it collects inventory-dollar-days until sold.