1. Z556: Session 8 Data Modeling
Entity-Relationship Diagram (ER).
Unified Modeling Language (UML).

2. Modeling Cultural Model Flow Model Physical Model Artifact Model
Sequence Model
E-R Diagram

3. What is Data Modeling?
A process for identifying, documenting & organizing data elements based on specified requirements.
It’s imp to know that Data modeling is not the beginning of the design process.
There are previous steps that need to be done before data modeling. You need to understand the problem, learn the current situation, identify the needs of the users, and identify the requirements for the systems. When you do that, you work on identifying the data elements that matter to solve the problem, and use modeling to document these elements and organize them to best serve your situation. 3

4. A design activity that is not limited to data analysis. (Be Creative…)
What is Data Modeling?
A design activity that is not limited to data analysis. (Be Creative…)
You need to know that data modeling is a design activity that is not limited to data analysis. Therefore, there can be many accepted solutions and designs that serve your purpose.
The decision of which design to implement depends on many factors, some of which are not at all related to the structure of the system.
And because it is a design activity, you can be creative, think outside of the box, show your unique touch in the design 4

5. Can be presented in many different ways.
What is Data Modeling?
Can be presented in many different ways.
E.g.,
Tables
Entity-Relationship diagram
Class diagram
Activity diagram
And because data modeling is a design activity, there many ways to document and organize the data elements. 5

6. Why Data Modeling?
To identify essential data elements and understand their role in supporting business processes.
Data modeling is used as a plan for developing applications, specifically how data is stored and accessed. 6

7. A Little Incentive to Pay Attention
Annual Mean Salary by Job
Financial specialist
$74,270
Information and Record Clerks
$32,320
Loan officer
$71,800
Network & Computer Systems administrator
$77,910
Paralegals
$51,170
Database administrator
$80,740
Advertising Sales Agents
$57,440
Actuaries
$107,740
Bureau of Labor Statistics

8. Data Modeling Language
Entity-Relationship (ER) Diagram Object-Oriented (OO) Design Unified Modeling Language (UML) 8

9. Case Study: KCCI Training Center
KCCI training center organizes training programs for customers in three different areas: Investment, Real-Estate, & Human-Resources.
For each program to run, there is a required minimum number of attendees.
To enroll in a program or more, a customer fills a registration form and send it to the center.
A training coordinator keeps track of the number of registered customers. When the minimum number is reached before the start date of the program, the coordinator contacts a trainer to run the program and then sends confirmation/invoice letters to the customers.
If no trainer is available or the minimum number is not reached, cancelation letters are sent to the customers.
One of the best way to learn a new language is to see how it is used.
So, this is an example of a real life case study.
Kuwait Chamber of Commerce and Industry (KCCI)

10. Case Study: KCCI Training Center
Problems:
Ineffective paper-based system that fails to meet the growing trends of the center.
Difficulty to track programs and participants.
Difficulty to locate misplaced or lost files.
Difficulty to share and access information.
Underutilized data for future planning.

11. Case Study: KCCI Training Center
Solution:
Develop a new information system for managing, storing, retrieving, and analyzing all information related to training programs.
Purpose of data modeling:
To identify essential data elements and understand their role in supporting work processes.

12. ER Diagram Entity Relationship Attribute
The principle data objects about which information is to be collected E.g., person, place, document, etc.
Entity instance: a particular occurrence of an entity.
What are the entities in the Training Center?
Instances
Indiana University Bloomington
University of Indianapolis
University of Phoenix
Entity name
University

13. ER Diagram Entity Relationship Attribute
Real-word association among entities.
Entity
Entity
Relationship
Manager
Department
Manages

14. ER Diagram Entity Relationship Attribute
Connectivity of a relationship :
Describes the constraints on the connection of the associated instance in the relationship.
A department has only one manager  a manager governs only one department
A department has many employees  an employee works in one department
A project involves many employees  an employee works on many projects.
In addition, you can express connectivity in terms of maximum or minimum.
Which one of these do you think is the most used and which one is the least used in data modeling?
Entity 1
Relationship 1
Entity
Entity 1
Relationship *
Entity
Entity *
Relationship *
Entity

15. ER Diagram Entity Relationship Attribute
Provides descriptive detail about entities and relationships.
An attribute value: a particular occurrence of an attribute within an entity or relationship.
Each entity has a key attribute used to uniquely determine an instance of an entity.
What type of connectivity in this relationship (enroll)? Many-to-many.
How can we solve this problem? Create weak entity “Registration form”.
Section ID
date
enroll
name
Student
Class
Title

16. KCCI ER Diagram Coordinator * * * Customer * * Program * Trainer Name
CoID
Name
is-contacted-by 1
Coordinator 1
contacts 1
Manages
Address
Date * * *
is given by
Customer *
enrolls *
Program * 1
Trainer
ProgID
Name
Name
CustID
TrnID
Area
Title
Phone

17. KCCI ER Diagram Coordinator * * * Customer * * Program * Trainer Name
CoID
Name
is-contacted-by 1
Coordinator 1
contacts 1
Manage
Address
Date * * *
is given by
Customer *
enrolls *
Program * 1
Trainer
ProgID
Name
Name
CustID
TrnID
Area
Title
Phone

18. KCCI ER Diagram Coordinator * * * Customer * * Program * Trainer
CoID
Name
is-contacted-by 1
Coordinator 1
contacts 1
Manage
Address
Date * * *
is given by
Customer 1 *
Registration Form * 1
Program * 1
Trainer
ProgID
Name
Name
CustID
TrnID
Area
Title
Phone

19. Implementing Entity (Customer) Cust# Name Address Phone # 100
Peter Alex
335 10th
Entity (Customer)

20. Implementing Attribute (address) Entity Cust# Name Address Phone # 100
Peter Alex
335 10th
data instance
Entity

21. Many-to-Many Relationship
Cust_id
F_name
L_name
address
1234
Mary
Gray
456 Oak street
1235
Bill
Dodds
789 Woodburn street
1236
Justin
Moore
903 College avenue
Registration
Class_id
Price
Date
Class name
135
100
Oct
Customer Service 101
136
200
Nov
Types of Investment
137
Oct
Property Evaluation

22. Many-to-Many Relationship
CUSTOMER
Cust_id
F_name
L_name
Address
REGISTRATION
Registration_id
Cust_id
Class_id
0088
1234
136
PRODUCT
Class_id
Price
Date
Class name

23. Generalization Hierarchy Diagram
Entities with common attributes can be generalized into a higher entity type (Superset entity). Subsets entities can be either disjoint (d) or overlapping (o).
ER diagram also supports the creation of a hierarchy diagram.
Disjoint: instance in one set cannot appear in another subset
Overlapping: an instance in one subset can appear in another subset. 23

24. Hierarchy Diagram d Overlap (o) Generalization
Disjoint (d) Generalization
Name
StartDate
Phone
ProgID
PerID
EndDate
Program
Person d o
Human-Resources
Customer
Trainer
Real-Estate
Investment
Coordinator

25. Object-Oriented (OO) Design
Objects are the basic unit which the organization must keep track of or that participate in a business process.
A system is a set of objects that collaborate and interact with each other.
UML is a widely accepted standard incorporating OO concepts, and provides terminology and diagram conventions.
UML is a language used to communicate between stakeholders and developers.
Language are best learned by practice.
What are the objects in the training center?
Similar to ER entities. 25

26. Object-Oriented Design
Properties attached to each object.
Attributes:
Functions that could change the value of object’s attribute.
Operations :
Procedure used to carry on the operations.
Methods:
What makes Object-Oriented model different from ER is that 3 types of information are associated with an object: 26

27. OO Concepts
Classes: Categories to which an object belong to and share the same operation, methods, and attributes.
Class Name
Attribute 1
Attribute 2
Attribute 3
Operation 1 ()
Operation 2 ()
Operation 3 ()
Customer
CustomerID
Name
Address
SearchProgram()
Enroll ()
Pay ()
Classes are categories to which an object belong to and share the same operation, methods, and attributes, but might not share the same attribute value.
Operations can include arguments to specify type of information or default value of the operation. 27

28. Class Relationships in UML
Generalization: A relationship between a more general class and a more specific class.
Association: Objects in one class linked to objects in the other class. Multiplicities: 1 to 1 , 1 to * , * to *
Program
Real-Estate
Investment
Human-Resources
Each object in the specific class is indirect object in the general class. Specific class inherits the features of the general class. 28
Coordinator
Program

29. Class Relationships in UML
Aggregation: Relationship between a whole and its parts.
Composition: An aggregation relation in which the part belong to only one whole at a time.
Trainer
Program
A part may belong to more than one whole.
ProgramDescripton
Program
Purpose
TargetAudience 29

30. UML Class Diagram (Attributes)
1..1
1..*
1..*
1..*
Trainer
<pk>TrainerID
Name
PlaceOfWork
Phone
Fax
Note
Program
<pk>ProgramID
Title
TrainingArea
Location
StartDate
EndDate
StartTime
EndTime
Cost
MinAttendees
Coordinator
Status
Note
Customer
<pk>CustomerID
Title
Name
Phone
Fax
Work
Note
1..1
1..1
RegistrationForm
<pk>RegFormID
Date
<pk>CustomerID
<pk>ProgramID
Note
1..1
1..*
Association Class
1..1
Invoice
<pk>InvoiceID
Date
RegistrationForm
Cost
Note
1..1
Coordinator
<pk>CoordinatorID
Name
Phone
Note

31. UML Class Diagram (Operation)
1..1
1..*
1..*
1..*
Trainer
AddTrainer()
RemoveTrainer()
isAvailable(:Boolean)
Program
AddProg ()
ConfirmProg ()
CancelProg()
Customer
NewCust()
SignIn()
FindProgram()
Enroll(in enrl: Program)
SendRegForm()
Payment()
1..1
1..1
1..*
RegistrationForm
AddProgram()
RemoveProgram()
AddCustomer()
RemoveCustomer()
1..1
Coordinator
ProgStatus ()
ConfirmLetter ()
CanelLetter ()
ContactTrainer()
Class diagrams provide the same opportunity to document data and their relationships as ER, but it also can captures operations.
An operation could have a parameter value placed between the parentheses "( )". The parameters can specify expected input or output data from each operation.
1..1
1..1
Invoice
Total (amnt: Dollar)

32. Summary
Data modeling help identify essential data elements and understand their role in supporting business processes.
Data modeling simplifies communication between system developers and end users.
Data modeling supports the development of information systems. 32

33. Develop a Data Model for Choosing a Job?
What are the entities/classes?
What are the attributes?
What are the relationships?
Entities: Person(name, , phone, CV), Job(title, salary, responsibilities, requirements, contactPerson), Organization (name, location, type, website) 33

34. Develop a Data Model for Choosing a Job?
1..1
1..*
1..*
1..1
ContactPerson
<pk>CP_ID
Name
Phone
Fax
Note
Job
<pk>JobID
<pk>CP_ID
<pk>OrgID
Title
Salary
Responsibilities
Requirements
StartDate
Location
Note
Organization
<pk>OrgID
Name
Phone
Fax
Website
Type
Note
Entities: Person(name, , phone, CV), Job(title, salary, responsibilities, requirements, contactPerson), Organization (name, location, type, website) 34

35. The 7 Habits of Highly Effective Data Modelers (Moody, 1996)
Knowledge
Skill
Motivation
Habit
Moody, D. (1996) The seven habits of highly effective data modelers.
Database Programming & Design, 9, 10,

36. The 7 Habits of Highly Effective Data Modelers (Moody, 1996)
See for yourself (observation—Method school of data modeling)
Generate alternatives
Keep it simple (generalization)
Test the model (prototyping/scenario)
Know when to stop
Remember the big picture
Following through
Contextual Inquiry

37. Object-Orientation Objects An object has attributes and operations
Color; Size
ILS Z556

38. Object-Orientation Objects An object has attributes and operations
Make a call
ILS Z556

39. Object-Orientation A class is a category to which an object belongs
E.g., Smartphone is a class for Nexus and iPhone; both share the same attributes and operations
ILS Z556

40. Object-Orientation Window is a class that has:
Attributes of: size, location, background color, etc.
ILS Z556

41. Object-Orientation Window is a class that has:
Operations of: open, close, resize, etc.
ILS Z556

42. UML and ER UML class diagrams =~ ER diagrams Classes =~ Entities
Attribute 1
Class Name
Attribute 1
Attribute 2
Operation 1()
Operation 2()
Entity Name

43. UML and ER UML class diagrams =~ ER diagrams Classes =~ Entities
Example
Class Name
Attribute 1
Attribute 2
Operation 1()
Operation 2()
Customer
<pk>Customer_id: string
Customer_name: string
Address: string
creditRating ()

44. UML and ER UML class diagrams =~ ER diagrams Classes =~ Entities
Example
Class Name
Attribute 1
Attribute 2
Operation 1()
Operation 2()
Customer
<pk>Customer_id: string
Customer_name: string
Address: string
creditRating ()
Create
Read
Update
Delete

45. UML: Class Diagram Customer Order association Payment aggregation
date
status
name
address 1
0..*
calcTax
calcTotal
calcTotalWeight
association
Payment 1 1
1..*
amount
aggregation
1..*
line item
OrderDetail
specialization
quantity
taxStatus
Credit
Cash
Check
calcSubTotal
calcWeight
number
type
expDate
cashTendered
name
bankID
authorized
authorized