This is UML basic about component , acitivity , statechart diagram.

1. UML Component Diagram

2. Overview
● Component diagrams are used to model
physical aspects of a system.
● Physical aspects are the elements like
executables, libraries, files, documents etc
which resides in a node

3. Purpose
● Visualize the components of a system.
● Construct executables by using forward and
reverse engineering.
● Describe the organization and relationships of
the components.

4. How to draw Component Diagram?
Before drawing a component diagram the following
artifacts are to be identified clearly:
● Files used in the system.
● Libraries and other artifacts relevant to the
application.
● Relationships among the artifacts.

5. How to draw Component Diagram?
Now after identifying the artifacts the following
points needs to be followed:
● Use a meaningful name to identify the component for
which the diagram is to be drawn.
● Prepare a mental layout before producing using tools.
● Use notes for clarifying important points.

6. Where to use Component
Diagrams?
Now the usage of component diagrams can be described as :
● Model the components of a system.
● Model database schema.
● Model executables of an application.
● Model system's source code.

7. UML Statechart Diagram

8. Overview
● It describes different states of a component in a
system.
●

9. Purpose
● To model dynamic aspect of a system.
● To model life time of a reactive system.
● To describe different states of an object during
its life time.
● Define a state machine to model states of an
object.

10. How to draw Statechart Diagram?
Need to identify :
● Important objects.
● States.
● Events.

11. Where to use Statechart Diagrams?
So the main usages can be described as:
● To model object states of a system.
● To model reactive system. Reactive system
consists of reactive objects.
● To identify events responsible for state changes.
● Forward and reverse engineering.

12. UML Activity Diagram

13. Overview
➢ Describe dynamic aspects of the system.
➢ Basically a flow chart to represent the flow form
one activity to another activity.
➢ The activity can be described as an operation of
the system.

14. Purpose
● Draw the activity flow of a system.
● Describe the sequence from one activity to
another.
● Describe the parallel, branched and concurrent
flow of the system.

15. How to draw Activity Diagram?
● Activities
● Association
● Conditions
● Constraints

16. Where to use Activity Diagrams?
● Modeling work flow by using activities.
● Modeling business requirements.
● High level understanding of the system's
functionalities .
● Investigate business requirements at a later
stage.