9-1 © Prentice Hall, 2004 Chapter 9: Analysis Classes Object-Oriented Systems Analysis and Design Joey F. George, Dinesh Batra, Joseph S. Valacich, Jeffrey A. Hoffer

Chapter © Prentice Hall, 2004 Chapter Objectives Af ter studying this chapter you should be able to: – Understand the three main kinds of analysis classes: entity, boundary, and control. – Draw a sequence diagram based on a use case description. – Translate a sequence diagram into a collaboration diagram.

Chapter © Prentice Hall, 2004 Chapter Objectives (Continued) Af ter studying this chapter you should be able to: – Convert a sequence diagram into analysis classes. – Understand the main kinds of business rules. – Draw an activity diagram and a statechart diagram.

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Chapter © Prentice Hall, 2004

Chapter © Prentice Hall, 2004 What Is an Analysis Class? A class that represents initial data and behavior requirements, and whose software and hardware-oriented details have not been specified Analysis class diagram – a UML diagram showing analysis classes and their relationships

Chapter © Prentice Hall, 2004 Stereotypes of Analysis Classes Mostly corresponds to conceptual data model classes Encapsulates connections between actors and use cases Mostly performs behaviors associated with inner workings of use cases

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Chapter © Prentice Hall, 2004 What Is a Sequence Diagram? A UML diagram that shows the interaction between objects to perform critical pieces of use case behavior in a time-ordered manner Interactions are in the form of messages Behavioral responsibilities are assigned to message recipients

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Chapter © Prentice Hall, 2004 Symbols in a Sequence Diagram Box or class stereotype symbol represents objects. Dotted vertical line represents object’s lifetime. Thin bars represent focus of control, periods of time when object is behaving (fulfilling responsibilities). Labeled horizontal lines represent messages passing between objects.

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Chapter © Prentice Hall, 2004 Typically, actors interact with boundary classes, which in turn interact with control classes, which in turn interact with entity classes.

Chapter © Prentice Hall, 2004 What Is Robustness Analysis? Involves analyzing the narrative text of each of the use cases and identifying a first-guess set of the objects into entity, boundary, and control classes Requires completeness checks and adherence to diagramming rules

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Chapter © Prentice Hall, 2004 What Is a Collaboration Diagram? A UML diagram that shows the interactions between objects to perform critical pieces of the use case behavior Unlike sequence diagrams, collaboration diagrams have no spatial representation of time; sequences of messages are shown by numbering.

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Chapter © Prentice Hall, 2004 Drawing Analysis Class Diagrams Analysis classes are completed by including operations, which fulfill the responsibilities taken by the analysis class. In addition, attributes and relationships from the conceptual data model are retained and refined.

Chapter © Prentice Hall, 2004 Operations (behaviors) are depicted in the lower third of a class box. Operations fulfill the class’s responsibilities.

Chapter © Prentice Hall, 2004 What Is an Activity Diagram? A diagram that emphasizes the flow of control from activity to activity in an object Similar to the traditional program flowchart Used to provide detail for complex algorithms

Chapter © Prentice Hall, 2004 Elements of Activity Diagrams Activity – a behavior that an object carries out while in a particular state Transition – a movement from one activity or state to another Decision point – a diamond symbol containing a condition whose results provide transitions to different paths of activities Synchronization bar – horizontal or vertical bars denoting parallel or concurrent paths of activities

Chapter © Prentice Hall, 2004 Activity diagram with a decision point One of the two possible paths will be selected for each execution

Chapter © Prentice Hall, 2004 Activity diagram with synchronization bars Top synchronization bar is a fork. Bottom synchronization bar is a join.

Chapter © Prentice Hall, 2004 What is a Statechart Diagram? A diagram that captures the behavior of an object by specifying the sequence of states it goes through during its lifetime in response to events, together with the responses to those events -State – a condition or situation during the life of an object at which time it satisfies some condition, performs some activity, or waits for some event. -All activities are states

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Chapter © Prentice Hall, 2004 What Is a Business Rule? A directive that is intended to influence or guide business behavior in support of business policy formulated in response to an opportunity or threat In information systems, business rules are implemented as data, constraints, and/or program code.

Chapter © Prentice Hall, 2004 Types of Business Rules Constraints – restrictions, mainly in the form of permissible values, validation rules, and multiplicities Calculations – mathematical formulas or algorithms that produce some value Value inferences – decision tables that result in attribute values being set Action enablers – decision tables that result in actions being taken

Chapter © Prentice Hall, 2004

Chapter © Prentice Hall, 2004

Chapter © Prentice Hall, 2004 Recap Af ter studying this chapter we learned to: – Understand entity, boundary, and control analysis classes. – Draw sequence diagrams, and convert to collaboration diagrams. – Convert sequence diagrams to analysis classes. – Understand the main kinds of business rules. – Draw activity and statechart diagrams.