1.
UML
Eng. Abd-ElRahman Hanfi

2.
Agenda
• Recap
• Behavior and Structure
• Class Diagram
• ERD Diagram
• Activity Diagram
UML 2

3.
Let’s Recap
UML what does it stand for ?
Why we are studying UML?
How we will apply UML?

4.
Unified Modeling language
Unified : To become united
Modeling : Something used as an example to follow or to
imitate
Language : Principle method for human communication
“SO it’s a standard way to communicate through
models”
UML standards identify 13 types of diagrams that are
divided into two groups.
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5.
UML Groups
Structural
Structural UML diagrams, as the name
would suggest, show how the system
is structured, including the classes,
objects, packages, components, etc. in
the system and the relationships
between those elements.
Behavioral
These UML diagrams
visualize how the system
behaves and interacts with
itself and with users, other
systems, and other entities.
UML 5

6.
Use case & sequence
Use case diagram Sequence diagram
UML 6

7.
Today’s subject :
• Class Diagram
• Activity diagram
• ERD diagram
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8.
Class diagram:
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• What is class diagram ?
• How to draw a class diagram ?
• Example

9.
Class diagram:
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• Class diagram is a structural diagram that shows the main structure of our system
• Used to display the classes of your system
• It gives you a static picture of the pieces in the system and of the relationships between them

10.
The components of A class diagram:
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11.
Cont.:
Class
A class represents an object
or set of objects that share a
common structure and
behavior (think of it as a
template)
Attribute
• piece of data containing
values describing each
instance of that class
Methods
• any behavioral features of
a class
Presentation Title 11

12.
Attributes :
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Class attribute (noun) :-
A class attribute is a significant piece of data containing values that describe each instance of that class
we can also call it variable or a property
An attribute consists of two parts :
1- data type
2- visibility :
- (+) public : meaning that the attribute is visible to all other classes
- (-) private : the attribute is not visible to any other class
- (#) protected : the class and any of its descendants have access to the attribute

13.
Method :
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Class method (verb):-
Is any behavioral feature of a class and we can also call it function or operation
An method consists of three parts :
1- operation name
2- operation parameters (input)
3- operation return type (output)
And it also has a visibility

14.
Example :
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15.
Relationships :
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Class relationships:
1-It shows how classes communicate with each others
2-It allows one class to know about the attributes, operations, and relationships of another class
Relationship types :
1- association (has A)
2- inheritance (is A)
3-aggregation (a whole -> parts)
4- composition (Whole kills parts)
5- reflexive relationships

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Multiplicity :
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Multiplicity :an indication of how many objects may participate in the given relationship or the allowable
number of instances of the element.

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EXAMPLE :
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18.
EXAMPLE :
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19.
EXAMPLE :
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20.
EXAMPLE :
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Activity diagram :
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• What is activity diagram ?
• How to draw activity diagram
• example

22.
Activity diagram :
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• Activity diagram is a flowchart to represent the flow of control among the activities in the system
• Activity diagrams describe the workflow behavior of a system
• Activity diagram illustrates the dynamic nature of a system by modeling the flow of control from
activity to activity

23.
Components of an AD:
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• Diagrams are read from top to bottom and have branches and forks to describe conditions
and parallel activities.
• A fork is used when multiple activities are occurring at the same time.
• A branch describes what activities will take place based on a set of conditions.
• All branches at some point are followed by a merge to indicate the end of the conditional
behavior started by that branch.
• After the merge all of the parallel activities must be combined by a join before transitioning into
the final activity state.

24.
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Activity Diagram:
Fork
Branch
Start State
Merge Join
Activity
End State

25.
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Example :
Fork
Branch
Start State
Merge Join
Activity
End State

26.
ERD :
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• What is ER diagram ?
• How to draw ER diagram
• example

27.
ERD :
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• a data modeling technique that graphically illustrates an information system’s entities and the
relationships between those entities.
• An Entity Relationship (ER) Diagram is a type of flowchart that illustrates how “entities” such as
people, objects or concepts relate to each other within a system
• Also known as ERDs or ER Models, they use a defined set of symbols such as rectangles,
diamonds, ovals and connecting lines to show entities, relationships and their attributes. They
mirror grammatical structure, with entities as nouns and relationships as verbs

28.
Components of ERD :
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• • ER Diagrams are composed of entities, relationships and attributes. They also depict cardinality,
which defines relationships in terms of numbers.
• An ERD entity is a definable thing or concept within a system, such as a person/role (e.g.
Student), object (e.g. Invoice), concept (e.g. Profile) or event (e.g. Transaction) (note: In ERD, the
term "entity" is often used instead of "table", but they are the same).
• Entity Attributes Also known as a column, an attribute is a property or characteristic of the
entity that holds it.
• Relationship A relationship between two entities signifies that the two entities are associated
with each other somehow. For example, a student might enroll in a course. The entity Student is
therefore related to Course, and a relationship is presented as a connector connecting between
them.

29.
Database design :
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• ER diagrams are used to model and design relational databases, in terms of logic and business
rules (in a logical data model) and in terms of the specific technology to be implemented (in a
physical data model.)
• In software engineering, an ER diagram is often an initial step in determining requirements for an
information systems project. It’s also later used to model a particular database or databases.

30.
Cardinality :
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• Defines the numerical attributes of the relationship between two entities or entity sets.
• The three main cardinal relationships are one-to-one, one-to-many, and many-many.
• A one-to-one example would be one student associated with one mailing address.
• A one-to many example (or many-to-one, depending on the relationship direction): One student
registers for multiple courses, but all those courses have a single line back to that one student.
• Many-to-many example: Students as a group are associated with multiple faculty members, and
faculty members in turn are associated with multiple students.

31.
PK :
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Primary Key
Also known as PK, a primary key is a special kind of entity attribute that uniquely defines a record
in a database table. In other words, there must not be two (or more) records that share the same
value for the primary key attribute. The ERD example below shows an entity 'Product' with a primary
key attribute 'ID', and a preview of table records in the database. The third record is invalid because
the value of ID 'PDT-0002' is already used by another record.

32.
FK :
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Foreign Key
Also known as FK, a foreign key is a reference to a primary key in a table. It is used to identify the
relationships between entities. Note that foreign keys need not be unique. Multiple records can share
the same values. The ER Diagram example below shows an entity with some columns, among which
a foreign key is used in referencing another entity.

33.
CPK :
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A Composite Primary Key
is created by combining two or more columns in a table that can be used to uniquely identify each
row in the table when the columns are combined.

34.
FK :
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35.
bridge table :
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Physical data modelling techniques transform a many-to-many many-relationships into one-to many-
relationships by adding additional tables.
Because many – many relationship may cause lack of performance
?

36.
FK :
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37.
FK :
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38.
ERD :
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39.
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Example :

40.
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41.
Content
Subtitle
• Add text, images, art, and videos.
• Add transitions, animations, and
motion.
• Save to OneDrive, to get to your
presentations from your computer,
tablet, or phone.
Subtitle
• Add text, images, art, and videos.
• Add transitions, animations, and
motion.
• Save to OneDrive, to get to your
presentations from your computer,
tablet, or phone.
Presentation Title 41

42.
Summary
UML diagrams can be used as a way to visualize a
project before it takes place or as documentation for a
project afterward. But the overall goal of UML
diagrams is to allow teams to visualize how a
project is or will be working, and they can be used
in any field, not just software engineering.
“Don’t forget to practice”
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43.
THANK YOU
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