Business rule is a vast topic and there are various books available that discuss it. In this section, we will give you a brief introduction to business rules and how to use and implement them.
We can think of a business rule as a plain set of words that say something meaningful about the business. For example: customers making a payment with a platinum card should be given a 20 percent discount on the purchase of products. This is a business rule, but it has been explained in simple words that a lay person can also understand.
To create and implement business rules, we require a business rule management system (BRMS) and Drools is an open source BRMS. To know more about Drools, you can refer to Drools JBoss Rules 5.0 Developer’s Guide, by Packt Publishing. In this chapter, we will cover just a brief overview of Drools. It is a JBoss project with the Apache license. The project consists of various modules, such as Drools Expert, Drools Guvnor, Drools Fusion...