Yazd University, Electrical and Computer Engineering Department Course Title: Advanced Software Engineering By: Mohammad Ali Zare Chahooki The Rational Unified Process (RUP) A Use-Case-Driven Process

Definitions  In this Lesson:  we focus primarily on one method of understanding and modeling the problem.  An effective method, and one  recommended by the RUP,  is the technique of use-case modeling 2

Definitions  Use cases:  provide a means of expressing the problem in a way  that is understandable to a wide range of stakeholders:  users,  developers, and  customers 3

Organizing Use Cases There are three ways to exploit commonality among use cases:  Inclusion  Extension  Generalization/specialization 4

Organizing Use Cases- Inclusion  Several use cases can include a common flow- of-event text organized as a use case.  In the ATM example, both Withdraw Money and Check Balance include "User enters PIN."  There is no need to express the flow of events associated with the entry of the PIN two or three times in the same model.  Both use cases could include a use case "Authenticate the User." 5

6 Organizing Use Cases- Inclusion

 The extension can be thought of as:  "injecting" additional descriptive text  into the extended use case,  at the extension point,  under particular conditions. 7 Organizing Use Cases- Extension

Unlike "include"  in which the basic flow of events is incomplete without the inclusion,  when you use "extend," the basic flow of events should still be complete; 8 Organizing Use Cases- Extension

 A use case can specialize more general one by  adding to or  refining the original flow of events.  For example, in an air traffic control system,  the Entry of an ICAO Flight Plan follows  the same basic principles and sequences of actions as the general Entry of a Flight Plan  but has some refinements as well as specific steps or attributes 9 Organizing Use Cases- Generalization

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 The Rational Unified Process is a use-case-driven approach.  This means that the use cases defined for a system are the basis for the entire development process 11 Use Cases in the Process

12 Use Cases in the Process

13 Use Cases in the Process