Use Case modeling is used to diagrammatically depict a system and those people or processes that interact with it. This system can be a business system (a process) or an application system (computer or web based). To understand the scope of the system under consideration a system boundary is used. Anything depicted within the system boundary is part of the system under consideration, while anything outside of it is not. Use cases are then used to define a group of user-system interactions that together deliver value to the user of the system. These users are called actors.