The document discusses the UML metamodel, including its design principles of modularity, layering, partitioning, and extensibility. It describes the organization of the UML specification into an infrastructure layer defining core metaclasses and a superstructure layer defining user-level constructs. Profiles are discussed as a means of customizing and extending UML for specific platforms and domains. Examples are provided of how different UML constructs like classes, activities, and interactions are represented in the metamodel.

1. Advanced Software Engineering
Paolo Bottoni
Block 3: The UML Metamodel

2. Overview
• UML layers of languages
• The UML Metamodel
• Profiles
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3. Design principles I
• Modularity
– Strong cohesion and loose coupling
– Gather group constructs into packages and
organize features into metaclasses
• Layering
– Layered package structure
• separate core constructs from higher-level ones
– 4-layer metamodel architectural pattern
consistently applied to separate concerns
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4. Design principles II
• Partitioning
– Used to organize conceptual areas within one layer
• Extensibility
– Profiles customize UML to platforms and domains
– Definition of new languages
• augmenting with metaclasses and metarelationships.
• Reuse
– Fine-grained, flexible library defines UML, MOF, CWM
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5. Organization of the specification
• Infrastructure
– Defines metalanguage core
– Contains metaclasses
• Reused for several metamodels, e.g. UML, MOF, CWM.
• Architecturally align UML, MOF, XMI: support model interchange.
• Superstructure
– Defines user level constructs of UML
– Classes derive from infrastructure classes
• Instances of metaclasses from the MOF
– Organized into language units
• Since version 2.5 infrastructure no longer separated
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6. Block3UMLMetamodel 6
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Root of Common structure

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Languages in UML

8. Types
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9. Relationships
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10. Classifiers
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11. Instances
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12. Features
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13. Multiplicities
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{ordered}

14. Expressions
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15. Block3UMLMetamodel 15
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Namespaces

16. Namespaces and Redefinitions
Element redefinition in the context of a generalisation
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17. Class
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18. DataTypes
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19. Packages
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20. Classes and Classifiers
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21. Block3UMLMetamodel 21
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Classes in
UML 2.5

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Metamodel for behaviours
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Metamodel for actions
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Invocation actions
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Object actions
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Metamodel for interactions

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Fragments

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Lifelines

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Metamodel for state machines
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Metamodel for activities

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Control nodes

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Object Nodes

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Metamodel for use cases

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From class diagrams …

35. … through the metamodel …
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36. … to its metamodel representation
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37. Block3UMLMetamodel 38
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Metamodel representation (State Machines)
s2:State
name=“SelectAmount”
s3:State
name=“EnterAmount”
s4:State
name=“ReleaseCard”
r1:Region
t1:Transition
t1:Transition
src
tgt
tgt
src
s1:State
name=“ReadAmount”
tr1:Trigger
name=“abort”
subvertex
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Adapting metamodels: profiling

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Profiles are packages

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Stereotypes are classes

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Stereotypes apply to classes

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Stereotype property as tagged value
DeploymentSpecification
deploymentLocation:String[0..1]
executionLocation:deploymentLocation:String[0..1]
<<stereotype>>
ConcurrencyMode
mode:{thread,process,none}
<<stereotype>>
TransactionMode
mode: {transaction,nestedTransaction,none}

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Usage of stereotype
<<concurrencyMode,transactionMode>>
infoStud:DeploymentSpecification
deploymentLocation=“Sapienza”
executionLocation=“Sapienza2”
<<concurrencyMode>>
mode=thread
<<transactionMode>>
mode=none

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The UML standard profile I

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The UML standard profile II

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A profile for EJB

47. • How to express the following:
1. Instances of a metaclass Entity must implement
a certain interface
2. Components can depend on interfaces
because they invoke their operations
3. Instances of Entity must have exactly one
attribute with name Id of type String
4. Instances of Entity must have exactly one
attribute of type EntityPK (as metaclass)
Some tests (and problems with
metamodeling)
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Correct or incorrect solution for 1.?

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What is this for?

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Correct or incorrect solution for 2.?

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attribute
attribute
Correct or incorrect solution for 3.?
attribute

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Correct and incorrect solutions for 4.
Property

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Metalevels and instanceof I ontological view

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Metalevels and instanceof II linguistic view