Use cases can be presented graphically in a diagram or inĪctivities performed in a use case may be categorized this way: Some systems are built entirely with only use case descriptions from sponsors. In the execution stage, use cases provide developers key parts of the specification.If the original actor gets sick, or perhaps even to use two children, one on the other's shoulders and together dressed to look like a single adult actor. Normally we'd like to pick the single actor providing the highest “quality of service”.īut we would also like the freedom to swap in a designated “second” The decision about who actually plays this role on stage is a separate “casting” decision. Without reference to the actor(s) playing this role. This definition is just a technical narrowing of the most common everyday sense of the word role.įor example, we can talk about the role of Hamlet in a particular performance, Independent of the object(s) that may implement it. Roles add a level of abstraction to object-based constructs.Ī role is an instance of an encapsulated set of properties and behavior,īut is described and used in a way that is totally They can surface often unspoken assumptions about the desired behavior of the system. Use cases helps to narrow the scope of the project. In the planning stage, the process of defining important use cases helps to clarify the most important goals of the system.Use cases are useful for several reasons throughout the development life cycle: Use cases identify the intent satisfying the role assumed byĮxternal “actors' interacting with the “system under discussion/test”.Ī primary actor is one having a goal requiring the assistance of the system.Ī secondary actor is one from which the system needs assistance to satisfy a goal. Use cases define the context of a system. UML Use Case diagram of the RUP Testing Discipline $35 Software Requirements (Addison-Wesley, January 16, 2002) Wiegers presents a jargon-free introduction to the best practices in requirementsįirst Edition (Microsoft Press August 26, 1999) Software Requirements, 2nd edition (Microsoft Press February 26, 2003)īy Karl E. Addison-Wesley, May 2001.Īpplies object-oriented technology to the business process engineering (BPR) model.īy Alistair Cockburn (name pronounced 'Coburn') of $45 The Object Advantage: business process engineering with object technology,īy Jacobson, I., Ericsson, M. $60 Object-Oriented Software Engineering: A Use-Case Driven Approach,īy Ivar Jacobson, et al.

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