1. Object Interaction – Interaction Overview Diagrams Timing Diagrams
Based on Chapter 9 of Bennett, McRobb and Farmer:
Object Oriented Systems Analysis and Design Using UML, (3rd Edition), McGraw Hill, 2005.
© Bennett, McRobb and Farmer 2005

2. In This Lecture You Will Learn:
how to model interactions using interaction overview diagrams;
how to model interaction using an interaction sequence diagram;
how to use timing diagrams.
© Bennett, McRobb and Farmer 2005

3. Interaction Overview Diagrams
Variants of activity diagrams (see Ch 5)
Focuses on the flow of control in an interaction
Nodes in the diagram may be interactions or interaction occurrences
Interaction needs to be broken down into its key elements.
© Bennett, McRobb and Farmer 2005

4. Interaction Overview Diagrams
An alternative version of the sequence diagram Add a new advert to a campaign if within budget is shown on the next slide and is used to develop an interaction overview diagram
© Bennett, McRobb and Farmer 2005

5. sd Add a new advert to a campaign if within budget
:Client
:Campaign
:Advert
getName
listCampaigns
ref
:CampaignManager
alt
[else]
sd Add a new advert to a campaign if within budget
List client campaigns
[totalCost <= budget]
Create advert
Create request
Get campaign budget
addCostedAdvert
© Bennett, McRobb and Farmer 2005

6. Interaction Fragment Used
:Campaign
:Advert
getCost
sd Get campaign budget
loop
getOverheads
checkCampaignBudget
:CampaignManager
[For all campaign’s adverts]
© Bennett, McRobb and Farmer 2005

7. Interaction Fragment Used
:Campaign
:Advert
Advert
newAd:Advert
sd Create advert
© Bennett, McRobb and Farmer 2005

8. Interaction Fragment Used
:Campaign
:Advert
newRequest:Request
Request
sd Create request
© Bennett, McRobb and Farmer 2005

9. Interaction occurrence In-line sequence diagram
sd Add a new advert to a campaign if within budget
sd List Campaigns for Client
:CampaignManager
:Client
:Campaign
getName
listCampaigns
loop
[For all client’s campaigns]
getCampaignDetails
Initial node
ref
Get campaign budget
Interaction occurrence
In-line sequence
diagram
sd Add costed advert
:Campaign
:CampaignManager
addCostedAdvert
Decision
[totalCost <= budget]
[totalCost > budget]
ref
ref
Create advert
Create request
© Bennett, McRobb and Farmer 2005
Final node

10. © Bennett, McRobb and Farmer 2005
Timing Diagrams
A new feature in UML 2.0
Show how time constraints affect interactions between lifelines
The sequence diagram Car enters car park is the basis for the subsequent timing diagram
© Bennett, McRobb and Farmer 2005

11. © Bennett, McRobb and Farmer 2005
Timing Diagrams
:TicketMachine
:Barrier
after:WeightSensor
sd Car enters car park
raiseBarrier
lowerBarrier
before:WeightSensor
activate
Raised
Lowered
Active
deactivate
Blocked
barrierLowered
Inactive
ticketRequested
© Bennett, McRobb and Farmer 2005

12. Timing Diagrams Sloped line represents duration of state change
sd Car enters car park lifelines :Barrier, :TicketMachine
:Barrier
:TicketMachine
Lowered
Raised
Inactive
Active
Blocked t
{t..t+3s}
Timing Constraint
raiseBarrier
barrierLowered
Diagram has two instances, one for each lifeline
Message from one lifeline to another
© Bennett, McRobb and Farmer 2005

13. © Bennett, McRobb and Farmer 2005
Model Consistency
Timing diagrams must be consistent with the relevant sequence diagrams and state machines.
© Bennett, McRobb and Farmer 2005

14. © Bennett, McRobb and Farmer 2005
Summary
In this lecture you have learned about:
how to model interactions using interaction overview diagrams;
how to model interaction using an interaction sequence diagram;
how to use timing diagrams.
© Bennett, McRobb and Farmer 2005

15. © Bennett, McRobb and Farmer 2005
References
UML Reference Manual (OMG, 2004)
Bennett, Skelton and Lunn (2005)
(For full bibliographic details, see Bennett, McRobb and Farmer)
© Bennett, McRobb and Farmer 2005