Entity relationship modeling visually represents entities, attributes, and relationships using entity relationship diagrams (ERDs). Peter Chen developed the original ERD format in 1976. Over time, a relational format evolved and is used by popular data modeling tools. The IDEF1X standard also specifies a format for ERDs. Process models include flowcharts, function hierarchy diagrams, swim lane diagrams, and data flow diagrams. A CRUD matrix relates database entities to business processes.

1. Data and Process
Modeling
Databases Demystified

2. Entity Relationship Modeling
 Entity relationship modeling is the process
of visually representing entities,
attributes, and relationships, producing a
diagram called an entity relationship
diagram.
 Peter Chen developed the original ERD
format in 1976.

3. Chen’s Format

4. The Relational Format
 Over time, an ERD format known
generically as the relational format
evolved.
 It is used by several of the better-known
data modeling software tools, including
PowerDesigner from Sybase and
ER/Studio from Embarcadero
Technologies, and in popular general
drawing tools such as Visio from the
Microsoft.

6. The IDEF1X Format
• The Computer Systems Laboratory of the
National Institute of Standard and
Technology released the IDEF1X standard for
data modeling in FIPS Publication 184.
• The standard covers both a method for data
modeling as well as the format for the ERDs
produced during the modeling effort.
• It is widely used and understood across the
information technology industry and is a U.S.
Federal Government standard.

8. Super Types and Subtypes

10. Process Models
 Flowchart
◦ (or structure chart) is probably the oldest form
of computer systems documentation.

12. The Function Hierarchy Diagram
 Shows all functions of a particular
application system or business process,
organized into a hierarchical tree.

14. The Swim Lane Diagram
• Gets it name from the vertical lanes in the
diagram, which resemble the lanes in a
swimming pool.
• Each lane represents an organizational
unit such as a department with process
steps placed in the lane for the unit that is
responsible for the step.
• Lines with arrows show the sequence or
control flow of the process steps.

16. The Data Flow Diagram
 The most data centric of all the process
diagrams.
 Instead of showing a control flow through
a series of process steps, it focuses
instead on the data that flows through the
process steps.

18. Relating Entities and Processes
 Use CRUD matrix (Create, Read, Update,
Delete)

20. Problems:
• A customer wants to order an item from a
fast-food store via an online self-service
kiosk system. To accomplish this, the
customer inputs his order via the kiosk's
touch screen user interface (UI). The UI logic
will make calls to the order service layer to
compute the total payment for the order.
Once the customer approves the total cost of
the order, the system will proceed to process
the payment. The system will then input the
order details into the order database and
provide a notification to the customer.

21.  A customer orders an item from a fast-
food counter. To accomplish this, the
customer states his order to the cashier.
Once he has ordered, the customer pays
the cashier for the food item. The
customer then receives the item ordered.
If for some reason the order is cancelled
after having paid for the item already, the
customer is refunded.