Business Rules

Business rules are rules or procedures that make or save the business money, irrespective of whether they were implemented on a computer. We call these rules Critical Business Rules, because they are critical to the business itself and would exist even if there were no system to automate them.

The busienss rules should be the most independent and reusable code of the system.

Critical Business Rules usually require some data to work with, we shall call it Critical Business Data. This is the data that would exist even if the system were not automated.

The critical rules and critical data are inextricable bound, so they are a good candidate for an object. We’ll call this kind of object an Entity.