1. UML and the Software Lifecycle

2. What is UML? Unified Modelling language
Developed to enable IT professionals to model computer applications in a standard language-independent way.
UML provides diagrams that increase the ease of understanding of an application under development

3. Main UML diagrams and the software Lifecycle
Use Case Diagrams
Activity Diagrams
Class Diagram
Sequence Diagrams
State Diagrams
Package Diagrams
Deployment diagrams
Requirements gathering
Requirements analysis
ANALYSIS
DESIGN
Software design
Implementation

4. Requirements Gathering: Use Case Diagram shows SCOPE
Source: IBM Rational

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7. Use Case Diagrams Business requirements – essential use cases Guest
Book
spa
Hotel self service subsystem
Check valid
room number
Order food/
drink
<<includes>>
Request
alarm call
Guest

8. Each Use Case Describes a system function from a user’s perspective
Details business events and users interaction with the system during that event
Represents a system activity, a well-defined part of the system’s functionality
Has a goal
Supported by behaviour specifications
Has a more detailed description, possibly specifying a number of scenarios or alternate courses of action

9. Use cases are initially defined at a high level and successively refined as the analysis and software development process unfolds.
Williams 2004

10. The UML Class Diagram provides a model that can be easily translated into software components.
Use case realisation includes identifying a set of classes with an understanding of how they work together to provide the functionality of the use case.
Williams 2004

11. Class Diagram static structure of the system
shows how different entities/objects relate
Can be used in analysis to show...
logical classes - things relating to the organisation
And in software design to show....
implementation classes, which are the things that programmers typically deal with.

12. The class diagram is refined and modified through the lifecycle to add more detail relevant to the implementation

13. Example class diagram 1 0..* Is made up of <boundary>
User Interface:: addmemberUI
Startnewmember()
Createnewmember()
Select membertype()
Recordpayment()
<control>
Control:: addmember
Select membertype()
Recordpayment()
Createnewmember()
<entity>
Member
Name
Address
Phone
Mobile
Type
Createnewmember()
Update membertype()
Updatememberdetails()
Deletemember()
<entity>
Filmclub
Club name
Location
Night
Time
Contact
Phone
Create filmclub() 1
0..*
Is made up of

14. Williams 2004

15. Class diagrams can show
Inheritance relationships
Association relationships (like in E-R diagrams)

16. Activity Diagrams
Activity diagrams are used to show sequences of activities.
show workflows from start point to finish point detailing the many decision paths that exist in the progression of events contained in the activity.
can be used to model higher-level business processes or low-level internal class actions.
Swim lanes can be used to show who is responsible for an action

17. Activity Diagrams

18. Activity diagram with swimlanes
Source: IBM Rational

19. Statechart Diagram
The statechart diagram models the different states that a class can be in and how that class transitions from state to state
Only necessary for classes with 3 or more states.

20. Statechart Diagram
Williams 2004

21. Sequence Diagrams Dynamic view of the system
represent or model the flow of messages, events and actions between the objects in a system.
show the calls between the different objects in their sequence for a use case or part of a use case
used to design, document and validate the architecture, interfaces and logic of the system

22. Sequence Diagrams

23. Williams 2004

24. Component Diagram physical view of the system
shows the dependencies that the software has on other software components (e.g. software libraries) in the system.
The diagram can be shown at a very high level, with just the large-grain components, or it can be shown at the component package level.
[Note: The phrase component package level is a programming language-neutral way of referring to class container levels such as .NET's namespaces (e.g., System.Web.UI) or Java's packages (e.g., java.util).]

25. Component Diagram
Source: IBM Rational

26. Deployment Diagram
shows how a system will be physically deployed in the hardware environment
where the different components of the system will physically run and how they will communicate with each other.

27. Deployment Diagram

28. Sources
Williams, Laurie (2004) An Introduction to the UML Modelling Language
IBM Rational - UML Overview