♦ Use Case Model  Detailled use case - Important  Use case diagram- Refactoring Use case diagram  > 1 Last Lectures

♦ DOMAIN Model Conceptual classes ( object, events, idea …etc ) A ttributes  Data value of an object.  To remember information Associations  Relationship between conceptual classes Multiplicities  many instances can be validly associated with another instance 2 Last Lectures

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System Sequence Diagrams Chapter 10 Applying UML and Patterns -Craig Larman

Introduction Class diagrams represent static modeling. What about modeling dynamic behavior? Interaction diagrams (Sequence and communication diagrams) model how groups of object collaborate to perform some behavior  Typically captures the behavior of a single use case Today´s lecture

System Sequence Diagram (SSD) For a use case scenario, an SSD shows: The System (as a black box) The external actors that interact with System The System events that the actors generate, their temporal order. :System

How to construct an SSD from a use case System Sequence Diagrams ♦ Draw a line representing the system as a black box. ♦ Identify each actor that directly operates on the system. Draw a line for each such actor. ♦ From detailled (expanded) use case identify system events that each actor generates. Illustrate them ♦ Optionally include use case text on left. 8

Develop SSDs for the main success scenario of a selected use case, then frequent alternative scenarios Relationship SSD and Use case

Process Sale

Relationship between SSD and Use case

Naming System events & operations System events and associated system operations should be expressed at the level of intent. Rather than physical input medium or UI widget Start operation names with verb (from use case) Which is better, scanBarCode or enterItem?

Naming System events & operations Capture the intent of the operation while remaining abstract

SSDs and the Glossary in parallel Why is updating the glossary important when developing the SSD? New terms used in SSDs may need explanation, especially if they are not derived from use cases A glossary is less formal, easier to maintain and more intuitive to discuss with external parties such as customers

Why Draw SSD? Actually, we investigate the behaviour of the system as black box (what system do). It is Important to know events that are coming in our system Later during design, the software is designed to handle these events In design, we will open the black box and look on how object collaborate to achieve what should be done

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Example 2 17

Question please!! 18