A business rule is an agreed statement as to how a particular aspect of business is conducted or should be conducted in the future. This includes the information system being built. Business rules tell you how "things are done" in a business and in its information systems.
Business Rules are the most important object in the USoft TeamWork data model and the central concept of the USoft methodology.
Business Rules are stated by management and end users in natural language (e.g., in English). Rules express the "way things are done" in the organization.
They are stated in a natural language, for example, in English or in Chinese, rather than in a formal language. Diagrams may be used to clarify aspects of Rules or applications, but they never replace the text format of Business Rules.
Here are a few examples of business rules: