The Pega Platform allows users to reuse RULES across case types and applications. Developers frequently reuse rules in their systems, RANGING from SINGLE data pieces to complete processes. Reusing rules increases the quality of an application while also cutting down on development time. Pega Platform divides rules into classes based on their re-usability INSIDE an application. Each cluster is referred to as a class. Each application is made up of three different class kinds.

• Work Class: Processes, data items, and user interfaces are all part of the Work class, which provides the rules that govern how to process a case or cases.
• Integration Class: The Integration class holds the rules that specify how the application interacts with other services, such as the integration resources that connect it to a customer database or a third-party web server.
• Data Class: The rules that specify the data objects used in the application, such as a customer data type or order items data type, are stored in the Data class.

When we add a rule in App Studio, it automatically SELECTS the proper class. We can concentrate on what we want the rule to accomplish rather than how to develop it. We can write the rule in Dev Studio if you need control over the class. Switching to Dev Studio is a good idea if we want to write a rule that we can reuse in another app.