1. The semantics of the UML Collaboration
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

2. Legal Notice This presentation is copyright
©1999 Trygve Reenskaug, Lasse Bjerde Oslo, Norway.
All rights reserved.
Unauthorized reproduction prohibited.
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

3. Summary Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

4. A system is a chosen perspective on reality
A system is a part of the real world which we choose to regard as a whole,
separated from the rest of the world during some period of consideration.
A whole that we choose to consider as a collection of parts,
each part being characterized by attributes and by actions which may involve itself and other parts.
Holbæk_Hanssen et.al.: System Description and the Delta Language
Oslo, 1977
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Trygve Reenskaug: Semantics of UML Collaboration

5. Consider the Universe as a Universe of objects
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Trygve Reenskaug: Semantics of UML Collaboration

6. The object paradigm is very simple
UML Class Abstraction cannot model message sends.
Use UML Collaboration abstraction for system modeling
Object-B IN
OUT-B
OUT-C
Methods
Variables IN
OUT-C
Object-C
Methods
Variables
Object Orientation
Encapsulation: Package data with methods; Collaborators only see object’s interfaces
Object identity supports Distributed logic: everything happens within some object, nothing outside the objects
Role models describe system behavior as object collaboration
Role model synthesis: Inherit collaboration with roles and system behavior
Essentially black box - implementation hidden/postponed
Object-A IN
Methods
Variables
Message (operation)
triggers method
causes response
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

7. Summary Collaborations model open systems
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

8. An Open System For a given system,
the environment is the set of all objects outside the system
whose actions affect it
or who are affected by the system,
and also those objects outside the system whose attributes are changed by its actions.
Etzioni: Modern Organizations
Prentice-Hall, 1964
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Trygve Reenskaug: Semantics of UML Collaboration

9. Open systems interact with environment objects
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Trygve Reenskaug: Semantics of UML Collaboration

10. The collaboration is a topological model of a system of objects
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Trygve Reenskaug: Semantics of UML Collaboration

11. Typing AssociationEndRoles
/ Father
/ Mother
Mother_Child_Intf
cashRequested()
Child_Mother_Intf
cashReceived()
/ Child
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

12. Summary ClassifierRole defined in terms of Collaboration instance
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

13. Collaboration (definition)
A Collaboration describes how a number of objects work together for a common purpose.
The structural aspect is a description of the responsibilities of each object in the context of the overall purpose of the collaboration;
and also the links that connect the objects into a communicating whole.
The dynamic aspect is a description of how stimuli flow between the objects to achieve the common purpose.
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

14. ClassifierRole (definition)
A classifierRole is a named slot for an object participating in a Collaboration.
Object behavior is represented by its participation in the overall behavior of the Collaboration.
Object identity is preserved through this constraint: "In an instance of a collaboration, each ClassifierRole maps onto at most one object."
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Trygve Reenskaug: Semantics of UML Collaboration

15. Summary Separation of concern: Horizontal: Subsystem object grouping
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

16. Separation of concern Cluster objects into “super-objects”
The (EJB) Component:
A Component has a single access point (an object ID) and offers a well-defined interface to its clients.
A Component is reused by cloning
A Component does not make assumptions about its clients
A Component plays a standardized role within a container
Tools are used to deploy components and compose systems
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Trygve Reenskaug: Semantics of UML Collaboration

17. Horizontal Separation of Concern Object clustering
«EJB»
BeanExample
UML 1.3 Subsystem
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Trygve Reenskaug: Semantics of UML Collaboration

18. Vertical Separation of Concern Collaborations separate on behavior
Collaboration for Use case / operation UC1
Collaboration for Use case / operation UC2
Object
Object
Object
Object A B C D
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Trygve Reenskaug: Semantics of UML Collaboration

19. Summary VirtualRole: package of ClassifierRole
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

20. Virtual Roles Example Activity Network
Activity-B
Activity-D
8 (4) 12
13 (3) 16
Activity-A
Activity-F
5 (3) 8
20 (4) 24
Activity-C
Activity-E
8 (5) 13
13 (7) 20
Completion time
Duration
Start time
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Trygve Reenskaug: Semantics of UML Collaboration

21. Virtual Roles Four designs
/ViewPackage
«virtualRole»
/ViewPackage
/ NetworkView
/ NetworkModel * 1
/ ActivityView 1 *
/ ActivityModel 1 * * 1
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Trygve Reenskaug: Semantics of UML Collaboration

22. VirtualRoles Use Case system
Function
Traveler
Paymaster
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Trygve Reenskaug: Semantics of UML Collaboration

23. Summary Virtual Interaction: Comment
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

24. Virtual Interactions - transfer information to view
- alert view of changes in model
«virtualRole»
«virtualRole»
/ View
/ Model
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

25. Summary Collaboration specifies system behavior
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

26. Role and system behavior The Collaboration
/ File
start() 1
read()
write()
stop() 1
/ Master 1
fileStarted()
runCompleted()
fileStopped() 1 *
/ Slave *
run()
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

27. Role and system behavior Message Sequence
/Master
/File
/Slave
start()
fileStarted()
run()
read()
readDone()
write()
writeDone()
runCompleted()
stop()
fileStopped()
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

28. Role and system behavior Role State Machines
Slave.readDone();
Idle
start/
open file;
master.fileStarted();
Ready
stop
/closeFile;
Master.fileStopped();
/ File
Done
Initial
read
/read();
write
/write();
Slave.writeDone();
Stopping
WaitComplete
WaitStart
/ Master
Initial/File.start();
fileStarted
/Slave.run();
runCompleted
/File.stop();
fileStopped
final
Idle
done
Editing
run/File.read();
writeDone
/Master.runCompleted();
readDone
/File.write();
/ Slave
Initial
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

29. Role and system behavior System State Machine
Initial->File.start();
Master-WaitStart & File-Idle & Slave-Idle
File start / open file; Master.fileStarted;
Master-WaitStart &
File-Ready
& Slave-Idle
Master fileStarted / Slave.run();
Master-WaitComplete
& File-Ready & Slave-Idle
Slave run / File.read()
Master-WaitComplete & File-Ready &
Slave-Editing
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

30. Summary Proposed metamodel extension
Collaborations model run-time system
Collaborations model open systems
ClassifierRole defined in terms of Collaboration instance
Separation of concern:
Horizontal: Subsystem object grouping
Vertical: Collaboration on behavior
VirtualRole: package of ClassifierRole
Virtual Interaction: Comment
Collaboration specifies system behavior
Proposed metamodel extension
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

31. Metamodel extension for Instance Level Collaboration
classifier
GeneralizableElement
Namespace
Classifier
(from Core)
1..*
(from Core)
(from Core)
1..*
base *
ClassifierRole
SpecificationCollaboration 1
ownedElement
(from Collaborations)
(from Collaborations)
1..*
multiplicity: Multiplicity 1
ModelElement
(from Core) * *
1..*
Instance *
InstanceCollaboration
(from Common Behavior)
instance
(new)
roleInstance
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

32. Metamodel extension for OCL Definition of Collaboration
context InstanceCollaboration inv:
self.specificationCollaboration.ownedElement->
forAll( c : ClassifierRole |
c.instance->select(i : Instance |
self.roleInstance->includes(i))->size <= 1)
My thanks to Jos Warmer
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration

33. THANK YOU
1/15/2019
Trygve Reenskaug: Semantics of UML Collaboration