Here we are trying to describe the UML diagrams. Those are Use-Case diagram, Activity Diagram, Sequence Diagram, Er Diagram, Class Diagram, Data-Flow Diagram. We describe the details figure of those diagrams.

1. UML Diagram
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2. Daffodil International University
SUBMITTED BY
 NILOY BISWAS (171-35-225)
 TANVIR ISLAM (171-35-239)
 RABIUL ISLAM (171-35-239)
 BORNA BHOWMICK (171-35-239)
Submitted to
RidwanullahYousuf
Lecturer,
Department of SWE
Daffodil International University
2
DATE: 08 April 20197/3/2019

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What is a use case diagram?
In the Unified Modeling Language (UML), a use case diagram can
summarize the details of your system's users (also known as actors)
and their interactions with the system. To build one, you'll use a set of
specialized symbols and connectors. An effective use case diagram
can help your team discuss and represent

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Purposes of use case diagrams:
 Used to gather the requirements of a system.
 Used to get an outside view of a system.
 Identify the external and internal factors the system.
 Show the interaction among the requirements are actors.

5. Use case Diagram
 Components of Use Case Diagram:
Use Case (function/operation)
Link
Relationship
Generalization
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7. Activity Diagram
 Activity diagram is basically a flowchart to represent the
flow from one activity to another activity. The activity can be
described as an operation of the system.
 The basic purposes of activity diagrams is similar to other
four diagrams. It captures the dynamic behavior of the
system.
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8.  Example of ATM transition
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9.  Sequence Diagrams are interaction diagrams that detail how
operations are carried out. They capture the interaction
between objects in the context of a collaboration.
 Purpose of Sequence Diagram
I. Model high-level interaction between active objects in a
system.
II. Model the interaction between object instances within a
collaboration that realizes a use case
III. Model the interaction between objects within a
collaboration that realizes an operation
Sequence Diagram
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10.  Example of Sequence diagram
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11. Components of a ER Diagram
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12. 1. Entity
An entity is an object or component of data. An entity is represented as
rectangle in an ER diagram.
For example: In the following ER diagram we have two entities Student and
College and these two entities have many to one relationship as many
students study in a single college. We will read more about relationships later,
for now focus on entities.
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13. 2. Attribute
An attribute describes the property of an entity. An attribute is represented as Oval in an ER
diagram. There are four types of attributes:
1.Key attribute
2. Composite attribute
3. Multivalued attribute
4. Derived attribute
1. Key attribute:
A key attribute can uniquely identify an entity from an entity set. For example, student roll number
can uniquely identify a student from a set of students. Key attribute is represented by oval same as
other attributes however the text of key attribute is underlined.
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14. 2. Composite attribute:
An attribute that is a combination of other attributes is known as composite attribute. For
example, In student entity, the student address is a composite attribute as an address is composed
of other attributes such as pin code, state, country.
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15. 3. Multivalued attribute:
An attribute that can hold multiple values is known as multivalued attribute. It is represented with
double ovals in an ER Diagram. For example – A person can have more than one phone numbers
so the phone number attribute is multivalued.
4. Derived attribute:
A derived attribute is one whose value is dynamic and derived from another attribute. It is
represented by dashed oval in an ER Diagram. For example – Person age is a derived attribute as
it changes over time and can be derived from another attribute (Date of birth).
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16. 3. Relationship
A relationship is represented by diamond shape in ER diagram, it shows the relationship among
entities. There are four types of relationships:
1. One to One
2. One to Many
3. Many to One
4. Many to Many
https://beginnersbook.com/2015/04/e-r-model-in-dbms/
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17. 1. One to One Relationship
When a single instance of an entity is associated with a single instance of another entity then it is
called one to one relationship. For example, a person has only one passport and a passport is
given to one person.
2. One to Many Relationship
When a single instance of an entity is associated with more than one instances of another entity
then it is called one to many relationship. For example – a customer can place many orders but a
order cannot be placed by many customers.
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18. 3. Many to One Relationship
When more than one instances of an entity is associated with a single instance of another entity
then it is called many to one relationship. For example – many students can study in a single
college but a student cannot study in many colleges at the same time.
4. Many to Many Relationship
When more than one instances of an entity is associated with more than one instances of another
entity then it is called many to many relationship. For example, a can be assigned to many projects
and a project can be assigned to many students.
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19. BLOODBANK ER Diagram
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20. Essential elements of UML class diagram are:
1.Class Name
2.Attributes
3.Operations
CLASS Diagram
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21. Relationships
There are mainly three kinds of relationships in UML:
1.Dependencies
2.Generalizations
3.Associations
Dependency
A dependency means the relation between two or more classes in which a change in
one may force changes in the other. However, it will always create a weaker
relationship. Dependency indicates that one class depends on another.
In the following example, Student has a dependency on College
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22. Generalization:
A generalization helps to connect a subclass to its superclass. A sub-class is inherited from its
superclass. Generalization relationship can't be used to model interface implementation. Class
diagram allows inheriting from multiple super classes.
Association:
This kind of relationship represents static relationships between classes A and B. For example; an
employee works for an organization.
Here are some rules for Association:
 Association is mostly verb or a verb phrase or noun or noun phrase.
 It should be named to indicate the role played by the class attached at the end of the
association path.
 Mandatory for reflexive associations
In this example, the relationship between student and college is shown which is studies.
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23. Multiplicity:
A multiplicity specifies whether the association is mandatory or not. It has some lower bound and
upper bound.
Let's say that that there are 100 students in one college. The college can have multiple students.
Aggregation
Aggregation is a special type of association that models a whole- part relationship between
aggregate and its parts.
For example, the class college is made up of one or more student. In aggregation, the contained
classes are never totally dependent on the lifecycle of the container. Here, the college class will
remain even if the student is not available.
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24. Composition:
The composition is a special type of aggregation which denotes strong ownership
between two classes when one class is a part of another class.
For example, if college is composed of classes student. The college could contain many
students, while each student belongs to only one college. So, if college is not
functioning all the students also removed.
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25. BLOODBANK CLASSDiagram
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26. Data-flow Diagram
 A Data flow diagram is a graphical representation of flow of data through
information system.
 DFD can be used to visualize a data processing
 DFD shows what kind of data will be input to the system and what data is
received as the input. Also
It tells where the data will come from and go to and where it is stored in the
process.
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 components of data-flow diagram

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 The process

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 The Flow

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 The store

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 The terminator

33.  Example of data-flow diagram
 Data flow diagram for a web based Online interview &
review system and some requirement for this project is –
1. This will be a web-based system.
2. Any people can give review or interview.
3. There will be a registration form for the user.
4. People can give review in any given topic.
5. People can give review in any given topic.
6. People also can give request for create new topic.
7. Admin approve the request and create the topic.
8. Admin manage video call for online interview.
9. For only viewing people do not need to register.
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34.  DFD level-0
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35.  DFD level-1
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36. References
www.smartdraw.com
en.wikipedia.org
www.lucidchart.com
www.stackoverflow.com
www.tutorialspoint.com
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37. THANK YOU
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