Allocating Manufacturing Overhead Via Direct Labor
In the early 1900s it was logical to allocate manufacturing overhead on the basis of direct labor hours (or direct labor cost). The manufacturing process was not automated, there were hardly any variations in the products made (think Model T cars), and customers did not demand such things as just-in-time (JIT) deliveries or bar coding. In those days, when manufacturers increased the amount of direct labor, there was likely to be a related increase in such things as the number of factory supervisors, the factory space to be maintained, and factory supplies and utilities consumed. In other words, there was a high degree of correlation between the quantity of direct labor used and the amount of manufacturing overhead used. By allocating manufacturing overhead on the basis of direct labor hours, a product requiring 30 direct labor hours would be allocated twice as much manufacturing overhead as a product requiring 15 direct labor hours.
Let's illustrate an overhead rate based on direct labor hours for a company that manufactures just two products, X and Y. (An annual rate is developed in order to have a constant overhead rate even when production volumes fluctuate from month to month.) For the upcoming year the company expects the following: