Fields Software Group announced the purchase by Burger King of a special computer software system known as Retail Intelligence Operations or ROI.

Randall K. Fields, chairman of Mrs. Fields Inc., and John E. Foley, vice president of management information systems, Burger King Corp., made the announcement.ROI is a knowledge-based propriety software system that has been developed by Mrs. Fields Cookies as a complete store information management system.

ROI software is now used by Mrs. Fields in all the company's U.S. retail stores and in the company's La Petite Boulangerie bakery stores.

The system provides corporate management with daily sales data and other vital information, but also serves as a local management tool for the store manager.