Three allocation methods can be used to allocate support departments costs to operating departments:
• Direct method
• Step-down method
• Reciprocal method
The direct allocation method (often called the direct method) is the most widely used method of allocating support department costs. This method allocates each support department’s costs directly to the operating departments. In this method costs accumulated in service departments are allocated to the manufacturing departments depending on the services that each of the manufacturing department requires from each of the service department. In this method, firstly, we have to identify the service carried out by each of the service department.
Step-down Method
In this method, the cost of service departments will be allocated to other service and operating departments depending on whether they provide services or not. In the method, first of all, the support departments should be ranked in the order that the step-down allocation will continue. The costs in the support department identified in the first-ranked are allocated to other support departments and operating departments in the ratio of their services. The costs in the second-ranked support department are allocated to support departments and business departments that have not yet been allocated. What is important here is that it does not return to the previously allocated support departments and does not give a share. This procedure is followed until the costs in the last-ranked support department are allocated to operating departments.
Reciprocal Method
This method is also known as algebraic method. The reciprocal allocation method allocates costs by explicitly including the mutual services provided among all support departments. Theoretically, the direct method and the step-down method are less accurate when support departments provide services to one another reciprocally. For example, the Plant Maintenance Department maintains all the computer equipment in the Information Systems Department. Similarly, Information Systems provides database support for Plant Maintenance. The reciprocal allocation method enables us to incorporate interdepartmental relationships fully into the support department cost allocations.
The advantage of the direct and step-down methods is that they are relatively simple to calculate and understand. However, with the ready availability of computer software to solve sets of simultaneous equations, the extra costs of using the reciprocal method will, in most cases, be minimal.