Chief functions of an organization are performed by operating departments. For instance, the chief functions of an accounting firm consist of services such as advisory and auditing. Support is provided by service departments to the operating department of an organization. For instance, service departments consist of management of human resource, executive management, payroll, and accounting. Service departments are not involved in activities through which revenues are generated. But the support of theirs is essential for the success of the operating departments ("Difference between service and operating departments - explanation and examples | Accounting for Management", 2018).