Chapter 5 - Data Modeling

Structure Model

• Describe data and information structures inherent in business process

• Create the blueprint for development of relational databases to support collection, aggregation, and communication of process information

Structure Model - Purpose

• Describe entities or things in domain of interest (ex: customers or orders)

• Describe relationships among these things (ex: customers make orders)

• Specify how many instances of one entity can be related to another (ex: customers can place multiple orders)

• Identify attributes/characteristics of entities and relationships (ex: customer name, address, phone number, etc.)

UML Class Diagram Building Blocks

• Classes

• Association

• Multiplicites

UML Class Diagram - Classes

• Separately identifiable collections of things about which the organizations wants to collect and store information

• Can represent organization resources (ex: machines, buildings, cash, investments)

• Can represent people (ex: customers or employees)

• Can represent events (ex: sales, purchases, cash receipts)

• Can represent conceptual structures (ex: accounts, product categories)

UML Class Diagram - Associations

• Depict business relationships between two classes

• Sometimes have verb phrases to further clarify relationships

UML Class Diagram - Multiplicities

• Minimum and maximum amount of times classes can be associated with each other

Attributes

• Columns in a table

• Data elements that describe the characteristics of instances in a class

• Ex: entity is customers, attributes are customer ID, name, address, etc.

Primary Key

• One or multiple attributes that uniquely identify each instant in a class/row

• NEVER null

Foreign Keys

• Allows tables to be linked to eachother

• Shows associations between tables

Other UML Relationship Notation

• Generalization

• Aggregation

• Composition

Other UML Relationship Notation - Generalization

• Allows for grouping of things that have common characteristics

Other UML Relationship Notation - Aggregation

• Describe classes that are connected but can exist outside of each other

• Ex: Players and Teams, players are on a team but can exist without each other

  

Other UML Relationship Notation - Composition

• Describe classes that are connected but cannot exist outside of each other

• Ex: Books and chapters, chapter cannot exist separately from books

  

Other Notations: Notes

• Allows modeler to add explanations or describe constraints

• Can be attached to class with dash lined

  

Other Notations: Role Designation

• Helps when association depends on specific role that object in class has

• Ex: The association between employees and project depend on type of employee

Other Notations: Constraints

• Modeled w/ notes or placed near the constrained end of an association

  

Many-to-Many Associations

• 0..* and 0..*

• 0..* and 1..*

• 1..* and 0..*

• 1..* and 1..*

Implementing a Database from a Class Diagram

1. Map classes to tables

2. Map classes attributes to assign PK

3. Map associations to FK

4. Create new tables for many-to-many relationships

   1. Implement relationship among table following diagram

Decision Categories

• Eligibility/Approval

• Validation

• Calculation

• Risk

• Fraud

• Opportunity

• Assignment

• Targeting

Types of Business Rules

• Obligatory: what SHOULD happen

• Prohibited: what should NOT happen

• Allowed: What is allowed under certain conditions