1. Analysis Modeling
Static Modeling

2. Requirements analysis
Results in static and dynamic models
Scenario models: use cases (static), swimlane diagrams (dynamic)
Class diagrams (static)
Flow oriented diagrams (dynamic)
Behavioral models: sequence diagrams (dynamic), state diagrams (dynamic)
These models bridge the gap between requirements and implementation (code)

3. Classes through Class diagrams
We’ve done use cases, time to move on to candidate classes, all of which should:
Retain information
Need services
Have multiple attributes
Have common attributes and operations
Be essential requirements (in the problem space)

4. Selecting classes: example
Run this slide to see animation
ATMUser
Yes
PinNum
Yes No
Maybe
retained information
needed services
multiple attributes
common attributes
common operations
essential requirements

5. Class diagrams A box with at least three compartments:
Student
A box with at least three
compartments:
Class name
Attributes
Operations
Responsibilities
User-defined compartment
Each class associated with
other classes
-major: String
-gpa: Real
-standing: String
+add(section: Section)
+drop(section: Section)
-- The set of students known to the registration system
-- An exception occurs if gpa falls below 2.0

6. Attribute syntax
[visibility] name [multiplicity] [:type] [=initial-value]
[{property-string}]
visibility: public “+”, protected “#”, or private “-”
name: capitalize first letter of each word that makes up the name, except for the first
multiplicity: number, range, or sequence of number or ranges.
type: built-in type or any user-defined class
initial-value: any constant and user-defined object
property-string: e.g, changeable, addOnly, frozen

7. Operation syntax
[visibility] name [(parameter-list)] [:return-type] [{property-string}]
visibility: “+”, “#”, “-”
name: verb or verb phase, capitalize first letter of every word, except first
parameter-list: coma separated list of parameters
return-type: primitive type or user-defined type
property-string: isQuery, sequential, guarded, concurrent

8. Example association
Student
Section
-major: String
-GPA: Real
-standing: String
-name: String
-capacity: Integer
+add(Student)
+drop(Student)
+checkPrereq(List<Student>)
+add(Section)
+drop(Section)
Here, a Student is associated with a Section; one or both need the other in order to function

9. Associations
An association is a structural relationship that specifies that objects of class may be connected to objects of another class
Associations typically represent “long-lived” relationships
In a library system a Person always has a name (association), but may infrequently have a book (dependency)

10. Association syntax Connect two classes Have labels and roles
Have multiplicities
Are directional (related to “has a” relationship) – the navigation
Think about which class needs to know about the other; which class is an attribute of the other? Why/when do I care?

11. Exercise: How many instructors can a class section have?
Student
Semester
1..*
0..* 1
0..8
1..*
Class Section
Instructor
1..3
0..6
1..*
<works for 1 1
1..*
Department
Course

12. How many instructors can a class section have? Answer: 1 to 3
Student
Semester
1..*
0..* 1
0..8
1..*
Class Section
Instructor
1..3
0..6
1..*
<works for 1 1
1..*
Department
Course

13. Attribute vs Association
name is the role on the association (attribute)
We generally don’t model built-in classes like String (they are just types for attributes)
joe: Student
Is basically the same as ...
-name: String = “Joe Jones”
name
joe: Student
Joe Jones : String 1

14. Types of associations Relation Generalization Association Dependency
Binary Association
N-ary Association
Aggregation

15. Generalization A triangle on the side of the general class
Same as inheritance hierarchy in Java
Opportunity for reuse
Graduate Student
Person
Student

16. Dependency
One class uses another, but it’s a weaker form of association
Not
necessarily
long-lived; the
depend-or can
exist without a depend-ee
in the system
Dashed line

17. Aggregation Means “part of” Symbolized by a white diamond Crust1 1 1
Sauce Serving 1 1
Pizza *
Order
1..3 1 1
Cheese Serving
0..9 1
4..*
Topping Serving
Slice

18. Composition
Like aggregation, but the component cannot survive on its own
Symbolized by a black diamond
Room
Building

19. Exercise
Take a look at
Does John McCain (who has 7 houses) have a problem using this system?
If Barack Obama decides to create a Federal sales tax, how would we change the system?
Why is there a display method in Item, Book, MusicCD and Software?
An ItemOrder is part of how many Orders?
Can you explain how a search works using this diagram?

20. Answer
Take a look at
Does John McCain (who has 7 houses) have a problem using this system?
Yes; only 2 addresses associated with a customer
If Barack Obama decides to create a Federal sales tax, how would we change the system?
add federalTax attribute to Order class
Why is there a display method in Item, Book, MusicCD and Software?
each subclass has its own implementation, even though one was inherited from the parent
An ItemOrder is part of how many Orders? 1
Can you explain how a search works using this diagram?
No; this is a static diagram, and does not show “flow” or actions

21. Quiz review
What two main components make up a class in a class diagram?
How do you represent an attribute? What are all the options/parts?
How do you represent a method? What are all the options/parts?
What is an association? Draw it.
What is a dependency? Draw it.
What is a generalization? Draw it.
What is an aggregation/composition? Draw it.
When do you include an attribute, as opposed to modeling it with an association?
What do the arrows mean on associations?
What do the multiplicities mean on associations?

22. In-class exercise Let’s make a class diagram for an ATM
Include a dependency
Include a generalization
Include a composition
Include all multiplicities
label all attributes
Complete the exercises at
Due next class

23. Team Project Examine the Quiz Game description/use cases
In your teams, come up classes;
At least one dependency, aggregation, and generalization
All associations must have navigations and multiplicities
All attributes and operations must have types and visibilities
Turn in this assignment through XP-Dev