UML (Unified Modeling
Language)
UML
• The static structure defines the kinds of the objects
important to a system and to its implementation as well as
relationship among the objects.
• The dynamic behaviour defines history of the objects
over time and the communication among the objects to
accomplish task.
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UML – some notation
• Object classes are rectangles with the name at the top,
attributes in the middle section (“compartment”) and
operations in the next compartment.
• Relationships between object classes (known as
associations) are shown as lines linking objects
• Inheritance is referred to as generalisation.
– It uses an open triangular arrow head
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UML diagrams
Structural View
Behavioral View
• Class Diagram
•Sequence Diagram
•Collaboration Diagram
•Object Diagram
•State-chart Diagram
User’s View
•Use Case
Diagram
•Activity Diagram
Implementation View
Environmental View
•Component Diagram
• Deployment Diagram
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The use-case view
The use-case view helps you to understand and use the
system. This view looks at how actors and use cases
interact. The diagrams in this view are:
– Use-case diagrams
– Sequence diagrams
– Collaboration diagrams
– Activity diagrams
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The use-case view
• This view contains a Main diagram by default. Additional
diagrams can be added throughout the analysis and design
process.
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The logical view
The logical view addresses the functional requirements of
the system. This view looks at classes and their
relationships. The diagrams in this view are:
– Class diagrams
– Statechart diagrams
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The logical view
• This view contains a Main diagram by default. Additional
diagrams can be added throughout the analysis and design
process.
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The component view
The component view addresses the software organization
of the system. This view contains information about the
software, executable and library components for the
system. This view contains only component diagrams.
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The component view
• The component view contains a Main diagram by default.
Additional diagrams can be added to this view throughout
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The deployment view
The deployment view shows the mapping of processes to
hardware. This type of diagram is most useful in a
distributed architecture environment where you might
have applications and servers at different locations. This
view contains only one diagram – the deployment
diagram.
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Use Case Diagrams
• Use case diagrams show the interaction of
users of the system with the functionality of
the system.
UseCase
• A use case is a functional component of the
system that accomplishes a specific task, and is
represented by an ellipse.
• An actor, depicted as a stickman figure, is a
user of the system performing a specific role.
Actor
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Types of Actors in use case diagram:
1. Primary Actors:
•
People who use the main system functions.
2. Secondary Actors
•
People that perform administration or
maintenance tasks.
3. Other systems:
•
The others systems with which the system must
interact.
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Use Case Diagrams
• Use case diagrams are used early in the development
process to refine the functional specifications, identify user
interface requirements, and to define the scope of the
project.
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Use-case diagrams
– Use-case diagrams present a high-level view of
system usage as viewed from an outsider’s (actor’s)
perspective.
– These diagrams show the functionality of a system or
a class and how the system interacts with the outside
world.
– Use-case diagrams can be used during analysis to
capture the system requirements and to understand
how the system should work.
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Use-case diagrams
– During the design phase, use-case diagrams specify the
behavior of the system as implemented.
– Rose automatically creates a Main use-case diagram in
the use-case view.
– There are typically many use-case diagrams in a single
model.
– Use case model represents the external view of system.
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Types of Use-case
1.Including Use Cases:
• Use cases may contain the functionality of another use case
as part of their normal processing.
• In general it is assumed that any included use case will be
called every time the basic path is run.
• An example of this is to have the execution of the use case
<Card Identification> to be run as part of a use case
<Withdraw>.
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1.Including Use Cases:
•Use Cases may be included by one or more Use Case, helping
to reduce the level of duplication of functionality by factoring
out common behavior into Use Cases that are re-used many
times.
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2. Extending Use Cases
• One use case may be used to extend the behavior of
another;
• this is typically used in exceptional circumstances.
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2. Extending Use Cases
• For example, if before modifying a particular type of
customer order, a user must get approval from some higher
authority, then the <Get Approval> use case may
optionally extend the regular <Modify Order> use case.
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Use-case Diagram
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Example:
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Extension , Specialization Of Use Cases
• Extensions:
– When the user is expected to make the optional
interactions or to handle an exceptional condition,
then the base use case is more or less valid, but
needs further extensions by way of addition or
minor modifications to complete the actor’s
request.
– We create a separate use case limited to the
deviation sought in the original use case .
– Extension are to be designed for handling
exceptional , one off request of the users.
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Extension , Specialization Of Use Cases
• Example:
In example of railway ticket booking , it is not expected
that the passenger would change the ticket choice from ‘
Chair Car ‘ to ‘Sleeper Car’. But at the very last moment ,
if the choice is changed to Sleeper Car , the use of the
extension use case will be different for ticket printing and
related process only.
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Extension , Specialization Of Use Cases
• Specialization:
– When an analysis is made of scenario , we will; come
across use case that need to be included in the system.
– In some cases, we will come across the situation where
the use case scope is common to some extent that the
preconditions and processes within the use case and
post conditions are common across all users.
– But in the same use case, we need to handle a special
scenario where most of the specifications are common
to the special case as well.
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Extension , Specialization Of Use Cases
Ticketing Book
Passenger
Extension
Ticket Booking with
Concession
Extension with
Concession in fare
Specialization
Journey and Tariff
Special conditions
Passenger from
Military Services
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Use Case Diagram Example
UseCase
On-line Registration System
viewCourseSchedule
«uses»
courseAvailability
Actor
Student
makeClassSelection
«uses»
«uses»
checkConflicts
verifyPrereqs
confirmEnrollment
Registrar
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Use Case Diagram Example
Figure 1.9: Use Case diagram for an Automated Teller Machine (ATM) system
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Use Case Diagram Example
• This Use Case diagram shows the interactions between the
use cases and actors of an ATM system.
• In this example, the bank's customer initiates a number of
use cases: Withdraw Money, Deposit Funds, Transfer
Funds, Make Payment, View Balance, and Change PIN.
• A few of the relationships are worthy of further mention.
• The bank officer can also initiate the Change PIN use case.
• The Make Payment use case shows an arrow going to the
credit system.
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Use Case Diagram Example
• External systems may be actors and, in this case, the credit
system is shown as an actor because it is external to the
ATM system.
• The arrow going from a use case to an actor illustrates that
the use case produces some information that an actor uses.
• In this case, the Make Payment use case provides credit
card payment information to the credit system.
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Benefits Of Use Case
– Ensures complete system documentation, as all
use cases are included with model , design and
details.
– Reduce the user’s need for training and hand-
holding in learning to operate the system.
– Use system more efficiently.
– Reduce the time for system maintenance.
– Obtain user’s fast acceptance of the system.
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