1. Object Oriented Modeling and Design
Agenda
Some of the methodologies developed in the 1980s &1990s
Rumbaugh et. al.’s Object Modeling Technique (OMT)
An Object Model
A dynamic model
A functional model

2. Survey of Object Oriented Methodologies
Some of the methodologies developed in the 1980s &1990s:
Many methodologies are available for system development
Each methodology is based on
Modeling the business problem and
Implementing in object-oriented fashion
Differs in
Documentation of information and
Modeling notations
We look at the methodologies developed by Rumbaugh et al., Booch, and Jacobson which are the origins of the Unified Modeling Language (UML) and the bases of the UA

3. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
Describes a method for the analysis, design, and implementation of a system using an object-oriented technique
Class attributes, method, inheritance, and association can be expressed easily
Well-suited for describing the object model or the static structure of the system
OMT consists of four phases, which can be performed iteratively:
Analysis: The results are object, dynamic and functional models.
System design: The result is a structure of the basic architecture of the system

4. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
Object design: This phase produces a design document, consisting of detailed objects and dynamic and functional models
Implementation: This activity produces reusable, extendible, and robust code
OMT separates modeling into three different parts:
An object model presented by the object model and the data dictionary
A dynamic model presented by the state diagrams and event flow diagrams
A functional model presented by data flow and constraints

5. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Object Model:
Describes the structure of objects in a system:
Object’s identity
Relationships to other objects
Attributes and
Operations
Represented graphically with an object diagram
Object diagram contains classes interconnected by association lines
The association lines establish relationships among the classes

6. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Object Model:
Many(zero or more)
Example – Bank system
number
balance
deposit
withdraw
createTransaction
Account
Withdraw
CheckingAccount
AccountTransaction
firstName
lastName
pinCode
Client
ClientAccount
CheckingSavingAccount
SavingsAccount
transDate
transTime
transType
amount
postBalance
Transaction
Specialization

7. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Dynamic Model :
Provides a detailed and comprehensive dynamic model
Used to depict states, transitions, events and actions
Represented by State Transition Diagram (STD)
State diagram relates events and states
State diagram is a graph whose nodes are states and whose directed arcs are transitions labeled by event names

8. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Dynamic Model :
State:
A state is an abstraction of the attribute values and links of an object
A state is drawn as a rounded box containing an optional name
Initial state – shown by a solid circle
Final state – shown by a bull’s eye
Dialing

9. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Dynamic Model :
Event and transition:
An individual stimulus from one object to another is an event
An event is something that happens at a point in time
When an event is received the next state depends on the current state as well as the event
A change of state caused by an event is a transition
Example for event and transition
Idle
off-hook
DialTone

10. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Dynamic Model :
Example:
off-hook
Idle
dialTone
on-hook
digit(n)
valid number
Connecting
Dialing
digit(n)
routed
called phone answers
Ringing
Connected
called phone hangs up
Disconnected

11. Survey of Object Oriented Methodologies
Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Functional Model:
Describing business processes without focusing on the details of computer systems
Shows the flow of data between processes in a business, It is captured using Data Flow Diagram (DFD)
DFD Consists of four symbols:
Process Data flow
Data store External entity
Verify password
User
Location

12. Rumbaugh et. al.’s Object Modeling Technique (OMT) :
OMT Functional Model:
Example:The ATM system
carsatium
ATM Card
reader
Bank code
Bad bank code
Select bank
Bank
card code
Invalid card code
Select card
User keyboard
entry
password
Card authorization
Verify password
Bad password
Account type
Select account
Bad account
account
balance
User screen
selection
Transaction failed
Update account
Amount
,transaction type
Cash receipt
user

13. Data Flow Diagram Level 0 DFD: Bank code ATM Card Bad bank code reader
Select bank
carsatium