ict117 week09 behavioural modelling

8/6/2019 ICT117 Week09 Behavioural Modelling

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PowerPoint Presentation for Dennis, Wixom, & Tegarden Systems Analysis and Design with UML, 3rd EditionCopyright 2009 John Wiley & Sons, Inc. All rights reserved.

Behavioural ModelingChapter 7: Dennis, Wixom and

Tegarden


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17 March, 2011 ICT117 Systems Analysis & Design, Semester 2, 2010

Includes John Wiley & Sons Inc material

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ObjectivesUnderstand the rules and style guidelines forsequence and communication diagrams andbehavioural state machines.Understand the processes used to createsequence and communication diagrams andbehavioural state machines.Be able to create sequence and communicationdiagrams and behavioural state machines.Understand the relationship between thebehavioural models and the structural andfunctional models.


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Key IdeasBehavioural models describe the internaldynamic aspects of an information systemthat supports business processes in anorganisationKey UML behavioural models are:

Sequence diagramsCollaboration diagramsStatechart diagrams


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BEHAVIOURAL MODELS


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Behavioural ModelsSystems have both static and dynamiccharacteristicsStructural models describe the static aspects of the

systemBehavioural models describe the dynamics and

interactions of the system and its components

Behavioural models describe how the classesin the structural models interact in supportof the use cases.


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INTERACTION DIAGRAMS


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Interaction DiagramComponentsObjects

an instantiation of a class

Operationsthe behaviours of an instance of a class

Messagesinformation sent to objects to tell them to execute

one of their behaviours


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Sequence DiagramsShow the objects that participate in a use-caseShow the messages that pass between thoseobjects for a particular use-case


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Sequence Diagram Syntax


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More Sequence DiagramSyntax


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Sample Sequence Diagram


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Steps to Build SequenceDiagramsSet the contextIdentify which objects will participateSet the lifeline for each objectLay out the messages from top to bottom of thediagram based on the order in which theyare sentAdd execution occurrence to each objects

lifelineValidate the sequence diagram


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BEHAVIOURAL STATE

MACHINES


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Behavioural State MachinesA dynamic modelShows the different states through which asingle object passes during its lifeState transitions are responses to eventsThe model shows the objects actionsTypically used just for complex objects withmultiple possible states


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Components of State MachinesStates (or Status)values of an objects attributes at a point in time

Eventschange the values of the objects attributesTransitionsmovement of an object from one state to another if

a (optional) guard condition is satisfied

Actionsatomic, non-decomposable processes


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State Machine Syntax


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Sample State Machine


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Steps to Build a State MachineSet the contextIdentify the initial, final, and stable states ofthe objectDetermine the order in which the object willpass through the stable statesIdentify the events, actions, and guardconditions associated with the transitionsValidate the behavioural state machine


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CRUD ANALYSIS


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CRUD AnalysisLabels object interaction in 4 possible waysCreate

Read

Update

Delete

Matrix representation of objects andinteractionsMost useful as a system-wide representation


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Sample CRUD Matrix

Each interaction between objects is labelled

according to its type, or is left blank if no

interaction occurs


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Next lectureDesign Modelsverify analysis modelsevolve them into design modelsPackagesdesign strategies

ict117 week09 behavioural modelling

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