modelling languages - · pdf file3 modelling technique models are written in a...
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Modelling LanguagesCONCEPTUAL DATA MODELLING
(c) 2017 Monique Snoeck
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Modelling language
• A Modelling language is a collection of modellingtechniques
• the Unified Modelling Language (UML) is a collection of over 9 different modelling techniques
1. Class diagrams
2. ...
3. ...
(c) 2017 Monique Snoeck
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Modelling techniqueModels are written in a “modelling technique”
= collection of symbols + composition rules
• Example• BPMN Process diagrams
(c) 2017 Monique Snoeck
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Modelling techniques• Modeling techniques range from
Purely textual to Purely formal
register anew member
front office
desk Use Case 1:
Register Member
Description:
Regsitration of a new member
Precondition:
Member does not exist yet.
Steps:
Input the member's details into
the system
Checks uniqueness of member
Register member in the system
LOAN_ITEM = <{borrow, return, lose}, create_item.classify.(borrow.return)*.(borrow.lose + 1).declassify. remove_item>
BOOK =<{renew},create_item.classify.(borrow.(renew)*.return)*.(borrow.(renew)*.lose +1).declassify.remove_item>
(BOOK)|a LOAN_ITEM ║ LOAN_ITEM = LOAN_ITEM BOOK LOAN_ITEM
VOLUME = <{}, create_item.classify.(borrow.return)*.(borrow.lose + 1).declassify.remove_item
UMLCD
(c) 2017 Monique Snoeck
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Modelling techniques• There is a plentitude of modelling techniques for IS
• Entity Relationship Modelling
• UML Class diagram
• UML State chart
• Flow Charts
• Process Diagrams
• Petri Nets
• Event Process Chains (EPC)
• ...
(c) 2017 Monique Snoeck
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Modelling techniques
• Different models are used for different phases and different viewpoints
• PhaseAbstract/Conceptual Detailed
Implementation Agnostic Implementation Oriented
• ViewpointsData perspective Behavioural perspective Interaction perspective
(c) 2017 Monique Snoeck
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Modelling techniques
• Some techniques address the same viewpoint & phase, but use different symbols
• Business process modelling• BPMN Process diagrams
• Petri Nets
• Conceptual data modelling
• ER modelling
• UML Class diagram
Task 1 Task 2
Person Subscription(1,1) (0,N)Name Date
Person
String Name
Subscription
TimeStamp: Date1 0..*
(c) 2017 Monique Snoeck
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Modelling techniques
Sometimes the same technique is used through different phases
UML class diagram used for conceptual modelling
versus
UML class diagram used for program design
(c) 2017 Monique Snoeck
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Data modelling techniques
Extended Entity Relationship modelling• Invented by Peter Chen for the conceptual design of
databases.
• Later extended with insights from semantic modelling Extended Entity Relation (EER) modelling
Person Subscription(1,1) (0,N)Name Date
(c) 2017 Monique Snoeck
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Data modelling techniques
• Information Engineering (Crow's foot notation)
Person Subscription
(c) 2017 Monique Snoeck
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Data modelling techniques• UML Class Diagram
• Part of Unified Modelling Language
• Originates from Object Oriented Programming
• Represents data aspect of classes
Person
String Name
Subscription
TimeStamp: Date1 0..*
(c) 2017 Monique Snoeck
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Entity Class Entity
Data modelling techniques
EER UML InformationEngineering
0..1 0..*(0..1) (0..n)
1..1 1..*(1..1) (1..n)
(c) 2017 Monique Snoeck
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