Accounting is a service function

Yes, Accounting would be a service function. A service is any business that provides a well "service".

There are 2 main types of business, Merchandising, where a business sells a product, such as Wal-Mart, Target, a local resteraunt.

Service, where the company is in business to provide a service, Accounting, Dry Cleaning, Landscaping.

Since accounting would be the provision of an Accounting Service, then it would be a service business.