© 2005 by Prentice Hall Appendix 3 Object-Oriented Analysis and Design Modern Systems Analysis and Design Fourth Edition Jeffrey A. Hoffer Joey F. George.

© 2005 by Prentice Hall© 2005 by Prentice Hall

Appendix 3Object-Oriented Analysis and

Design

Modern Systems Analysisand Design

Fourth Edition

Jeffrey A. Hoffer Joey F. George

Joseph S. Valacich

© 2005 by Prentice Hall© 2005 by Prentice HallAppendix 3-2

Learning ObjectivesDefine events, state transitions, and

sequence diagrams.Describe concepts and principles of object-

orientation.Describe activities of the different phases of

object-oriented development.Compare object-oriented modeling with

traditional systems development approaches.Develop dynamic models with state,

interaction, and activity diagrams.Model real-world applications with UML.


The Object-Oriented Development Life Cycle

Process of progressively developing representation of a system component (or object) through the phases of analysis, design, and implementation

The model is abstract in the early stages

As the model evolves, it becomes more and more detailed


Object oriented cycle is like an onion, evolving from abstract to detailed, from external qualities to system architecture and algorithms.


Object-Oriented Deliverables and Outcomes

1. The ability to tackle more challenging problem domains

2. Improved communication among users, analysts, designers, and programmers

3. Increased consistency among analysis, design, and programming activities

4. Explicit representation of commonality among system components

5. Robust systems6. Reusability of analysis, design, and programming

results7. Increased consistency among the models developed

during object-oriented analysis, design, and programming


The Unified Modeling Language (UML)

A notation that allows the modeler to specify, visualize, and construct the artifacts of software systems, as well as business modelsTechniques and notations:

Use cases Class diagrams State diagrams Sequence diagrams Activity diagrams


Use Cases Revisited

A depiction of a system’s behavior or functionality under various conditions as the system responds to requests from users

Full functioning for a specific business purpose

See Chapter 7



Class Diagrams Revisited

Features: Objects and classes Encapsulation of attributes and operations Polymorphism Inheritance Aggregation and composition

See Chapter 9



Dynamic Modeling

Representation of activities that occur throughout the lifetime of a systemTypes of UML dynamic models State diagram: state changes within an

object Sequence diagram: time-sequenced

interactions between objects Activity diagram: flow of control between

activities within an object


State DiagramsState

A condition during the life of an object during which it satisfies some conditions, performs some actions or waits for some events

Shown as a rectangle with rounded cornersState Transition

The changes in the attribute of an object or in the links an object has with other objects

Shown as a solid arrow Diagrammed with a guard condition and actionEvent

Something that takes place at a certain point in time, triggering a state transition


State diagram: a model of the states of a single object and the events that cause the object to change from one state to another

Guard condition

Guard condition

Action

A transition is labeled with a guard condition and/or an action, separated with a forward slash /


Diagramming Substates and Decomposing States

A state can be expanded into substates using nested state diagrams, similar to expansion of processes in different levels of DFDs.


Diagramming Substates and Decomposing States

An event can be expanded into using nested state diagrams, and may involve substates and subtransitions and events.


Dynamic Modeling:Sequence Diagrams

A depiction of the interaction among objects during certain periods of timeElements of a sequence diagram

Objects: represented by boxes at top of diagram Lifeline: the time during which an object exists Activation: the time period during which an

object performs an operation Messages: means by which objects

communicate with each other


Types of Messages in Sequence Diagrams

Synchronous message The caller must wait for the receiving object to

finish executing the called operation before it can resume execution itself

Asynchronous message The caller can resume execution right after

sending the message, without waiting for the receiver to complete

Simple message A message that transfers control from the sender

to the recipient without describing the details of the communication

20.1720.17


time

lifeline

activation

message

object


Process Modeling:Activity Diagrams

Shows the conditional logic for the sequence of system activities needed to accomplish a business process

Clearly shows parallel and alternative behaviors

Can be used to show the logic of a use case


Elements of Activity DiagramsActivity: a behavior that an object carries out while in a particular stateTransition: a movement from one activity or state to anotherBranch: 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

Fork: the beginning of parallel activities Join: the end of parallel activities

Swimlanes: columns representing different organizatonal units of the system


swimlane

activity

branch

synchronization bar


Analysis Versus DesignStart with existing set of analysis modelProgressively add technical detailsDesign model must be more detailed than analysis modelComponent Diagram A diagram that shows the software components or

modules and their dependencies

Deployment Diagram A diagram that shows how the software

components, process and objects are deployed into the physical architecture of the system



SummaryIn this chapter you learned how to: Define events, state transitions, and sequence

diagrams. Describe concepts and principles of object-

orientation. Describe activities of the different phases of object-

oriented development. Compare object-oriented modeling with traditional

systems development approaches. Develop dynamic models with state, interaction, and

activity diagrams. Model real-world applications with UML.

© 2005 by Prentice Hall Appendix 3 Object-Oriented Analysis and Design Modern Systems Analysis and Design Fourth Edition Jeffrey A. Hoffer Joey F. George.

Documents

prentice hall appendix

state diagrams state

state transition slide

programming slide

detailed slide

valacich slide

nested state diagrams

object sequence diagram