Cost Drivers
A cost driver is a variable, such as the level of activity or volume, that causally affects costs over a given time span. An activity is an event, task, of unit of work with a specified purpose-for example, designing products. Setting up machines, or testing products. The level of activity or volume is a cost driver if there is a cause-and-effect relationship between a change in the level of activity or volume and a change in the level of total costs. For example, if product-design costs change with the number of parts in a product, the number of parts is a cost driver of product-design costs. similarly, miles driven is often a cost driver of distribution costs.