This document introduces various types of diagrams and how they can be used. It discusses entity relationship diagrams (ERD), which are used to design and document databases by showing entities, attributes, and relationships. It also covers process flow diagrams (PFD), which illustrate the steps in a process, and data flow diagrams (DFD), which show how data moves through a system. DFDs have three levels - level 0 gives an overview, level 1 breaks it into processes, and level 2 adds more detail. The document provides tips on drawing each type correctly and lists some common diagramming tools.

1. INTRODUCETO DIAGRAMS
WHY/WHEN/HOW USETHEM
Designed by Huong NgocVo

2. WARM-UP
Prepare for your brain

3. Why should we know about diagrams?
■ Natural language may arise misunderstanding.
■ Complex concepts/processes are hard to transfer literally.
■ Image speaks louder than words.
(Human brain can process images up to 60,000 times faster than words)
=> A standard, common convention to help everyone to gain and share same recognition
visually.

4. When can we use diagrams?
■ Capture, clean, and develop ideas
■ Transfer and present ideas/information
■ Keep information

5. FIGHTING!
Common baby!

6. ROUND ONE: ERD
Entity Relationship Diagram

7. ERD – Entity relationship diagram
What’s it?
Chen’s notation
Crow’s Foot notation

8. ERD – Entity relationship diagram
When is it used?
■ Design/Debug database
■ Gather requirements.
■ Understand system from data model aspect.
■ Document system.

9. ERD – Entity relationship diagram
How to use it?
■ For beginner, student who starts learn how to architect database: using Chen’s
notation to learn about how architect database
■ For database senior/expert: use Crow’s Foot notation

10. ERD – Entity relationship diagram
Steps to draw an ERD
■ Main Entity: people/ object/ concept.
Entity name must be a noun.

11. ERD – Entity relationship diagram
Steps to draw an ERD
■ Main Entity: people/ object/ concept.
Entity name must be a noun.
■ Relationship: what an entity can do
with another entity.Action must be a
verb

12. ERD – Entity relationship diagram
Steps to draw an ERD
■ Main Entity: people/ object/ concept.
Entity name must be a noun.
■ Relationship: what an entity can do
with another entity.Action must be a
verb
■ Attribute: both entity and
relationship has its attribute.

13. ERD – Entity relationship diagram
Steps to draw an ERD
■ Main Entity: people/ object/ concept.
Entity name must be a noun.
■ Relationship: what an entity can do
with another entity.Action must be a
verb
■ Attribute: both entity and
relationship has its attribute.
■ Cardinality: how many instances of
an entity relate to one instance of
another entity

14. ERD – Entity relationship diagram
Steps to draw an ERD
■ Strong Entity: people/ object/
concept.
■ Relationship: what an entity can do
with another entity.
■ Attribute: both entity and
relationship has its attribute.
■ Cardinality: how many instances of
an entity relate to one instance of
another entity.
■ Weak Entity: grow up from many-to-
many relationship, relationship has
attribute.

15. ERD – Entity relationship diagram
Steps to draw an ERD
■ Strong Entity: people/ object/ concept.
■ Relationship: what an entity can do
with another entity.
■ Attribute: both entity and relationship
has its attribute.
■ Cardinality: how many instances of an
entity relate to one instance of another
entity.
■ Weak Entity: grow up from many-to-
many relationship, relationship has
attribute.
■ Identify Primary key, Foreign key

16. ERD – Entity relationship diagram
Steps to draw an ERD

17. ERD – Entity relationship diagram
Level of ERD

18. ROUNDTWO: PFD
Process Flow Diagram

19. PFD – Process Flow diagram
What’s it?

20. PFD – Process Flow diagram
When is it used?
■ Develop understanding about one process
■ Communicate/explain/gain knowledge about how something work
Tell a story about your jobs by pictures
■ Plan/Debug / Improve process

21. PFD – Process Flow diagram
Common Symbols
■ Start and end point.
■ Step in process: handle main jobs
■ Direction of flow from one step or decision to another.
■ Decision based on a question.
■ Input or output.
■ Document.
■ Delay or wait.
■ Link to another page or another flowchart.

22. PFD – Process Flow diagram
Steps to draw a PFD
■ Define the process.
■ Identify the process’s boundaries of the process:
– Start: when and where
– End: when and where
– Level of detail
■ Brainstorm the activities/inputs/outputs.
■ Arrange the activities in proper sequence.
■ Draw arrows to show the flow of the process.

23. PFD – Process Flow diagram
Tips
■ Use swim lane
■ Add note/comment: decision
■ Number step

24. ROUNDTHREE: DFD
Data Flow Diagram

25. DFD – Data Flow diagram
What’s it?

26. DFD – Data Flow diagram
What’s it?
■ Shows the way information flows through a process or system
– What kind of information will be input to and output from the system
– How the data will advance through the system
– Where the data will be stored
■ Combine with ERD

27. DFD – Data Flow diagram
What’s it?

28. DFD – Data Flow diagram
When is it used?
■ Create an overview of the system without going into great detail
■ Debug system

29. DFD – Data Flow diagram
Three levels of DFD – Level 0

30. DFD – Data Flow diagram
Three levels of DFD – Level 1

31. DFD – Data Flow diagram
Three levels of DFD – Level 2

32. DFD – Data Flow diagram
Steps to draw DFD – level 1.
■ Think about the context. ■ ONLINEORDER SYSTEM

33. DFD – Data Flow diagram
Steps to draw DFD – level 1.
■ Think about the context.
■ Collect all the processes/external
entities/ inputs/ outputs/ data stores.

34. DFD – Data Flow diagram
Steps to draw DFD – level 1.
■ Think about the context.
■ Collect all the processes/external
entities/ inputs/ outputs/ data stores.
■ Arrange processes/external entities/
data stores in proper sequence.

35. DFD – Data Flow diagram
Steps to draw DFD – level 1.
■ Think about the context.
■ Collect all the processes/external
entities/ inputs/ outputs/ data stores.
■ Arrange processes/external entities/
data stores in proper sequence.
■ Draw arrows to show the flow of the
processes/external entities/ data
stores.

36. DFD – Data Flow diagram
Steps to draw DFD – level 1.
■ Think about the context.
■ Collect all the processes/external
entities/ inputs/ outputs/ data stores.
■ Arrange processes/external entities/
data stores in proper sequence.
■ Draw arrows to show the flow of the
processes/external entities/ data
stores.
■ Identify input/outputs each data
flow.

37. DFD – Data Flow diagram
Tips
■ Each process should have at least one input and an output.
■ Each data store should have at least one data flow in and one data flow out.
■ Data stored in a system must go through a process.
■ All processes in a DFD go to another process or a data store.

38. STRENGTHEN
You rock!

39. UML Diagrams
https://www.uml-diagrams.org/uml-25-diagrams.html

40. Architecture Diagram

41. Mind Map

42. Fishbone Diagrams
Cause and effect/ Ishikawa diagram

43. UX Maps

44. Empathy Map

45. BPMN
Business Process Management Notation

46. Tools to draw these chart
■ Office (not recommend)
■ Draw.io
■ Lucidchart.com
■ Smartdraw.com
■ Gliffy (chrome extension)
■ Visual Paradigm
■ Start UML

47. RELAX

48. SUM-UP
■ Visualize/Develop/Communicate your job to help understand easier.
■ ERD: data model
■ PFD: how process run
■ DFD: how system communicate (process and data)