UML component diagrams model physical aspects of a system such as executables, libraries, and files. They visualize component relationships and allow constructing executables through forward and reverse engineering. Component diagrams identify artifacts, draw components and their relationships, and can model systems, databases, executables, and source code. UML statechart diagrams describe component states and state transitions triggered by events. They model dynamic and reactive systems by defining state machines. UML activity diagrams represent system flows as activities and depict sequential, parallel, branched, and concurrent flows. They model work flows, business requirements, and system functionalities at a high level.

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.