Often, committed resources are acquired in advance for resource demands are known. Leasing or buying a building is an example. Buying multiperiod activity capacity is often done by paying cash front. In this case, annual expense may be recognized, but no additional resource spending is needed Up-front resource spending is a sunk cost and never relevant. Periodic resource spending, such as leasing, is independent of resource usage. Even if a permanent usage is experienced, is difficult to reduce resource spending