Modeling concept (state modeling and Interaction Modeling)

1. Prepared By:
Jesadiya shilpa

2. State Modeling & Interaction
Modeling

3. Introduction
• The State Model describes the sequence of
operations that occur in response to external
stimuli .
• The State Model consists of multiple state
diagrams, one for each class with temporal
behavior that is important to an application.
• The State Diagram is a graphical representation of
finite state machines that relates events and
states.
• Events represent external stimuli and state
represent values of objects.

4. Events, Conditions, and States
• Event: something that happens at a point in time
• Operator presses self-test button
• The alarm goes off
• Condition: something that has a duration
• The fuel level is high
• The alarm is on
• State : an abstraction of the attributes and links of an object (or entire
system)
• A state represent the current status of an object and it’s properties.

5. 5
States
– At any given point in time, the system is in one state.
– It will remain in this state until an event occurs that
causes it to change state.
– A state is represented by a rounded rectangle
containing the name of the state.
– Special states:
• A black circle represents the start state
• A circle with a ring around it represents an end state

6. STATE MODELING : EVENT S
• Kinds of Events
• Signal Event: It is an explicit one-way transmission (sending or
receiving a signal) of information from one object to another.
• Change Event: It is an event that is caused by the satisfaction of a
boolean expression. When keyword is used followed by
parenthesized boolean expression.
Ex: when(room temperature < heating set point) ,
when(battery power < lower limit)
• Time Event: It is an event caused by the occurrence of an absolute
time or the elapse of a time interval. When or after keyword is used
followed by parenthesized expression involving time.
Ex: when(date=January 1, 2010) ,after(10 seconds)

7. 7
Transitions
– A transition represents a change of state in
response to an event.
• It is considered to occur instantaneously.
– The label on each transition is the event that
causes the change of state.

8. 8
State Diagrams
• A state diagram describes the behaviour of a
system, some part of a system, or an individual
object.
– At any given point in time, the system or object is in a
certain state.
• Being in a state means that it is will behave in a specific way
in response to any events that occur.
– Some events will cause the system to change state.
• In the new state, the system will behave in a different way to
events.
– A state diagram is a directed graph where the nodes
are states and the arcs are transitions.

9. State Diagram
• General form of state diagram.
A B
C
event-1
event-2event-2

10. STATE DIAGRAM: THREAD LIFE CYCLE

11. • The class model describes the class & objects in a
system and their relationship.
• The state model describes the life cycles of the
objects.
• The interaction model describes how the objects
interact.
• The interaction model starts with use cases that
are then elaborated with sequence and activity
diagrams
Interaction Models

12. • Use case: focuses on functionality of a system-
i.e, what a system does for users
• Sequence diagrams: shows the object that
interact and the time sequence of their
interactions
• Activity diagrams: elaborates important
processing steps
Interaction Models

13. Use Case Diagrams

15. • Use Case diagrams show the various activities
the users can perform on the system.
– System is something that performs a function.
• They model the dynamic aspects of the system.
• Provides a user’s perspective of the system.
Use Case Diagrams

16. • Use Case diagrams show the various activities the users
can perform on the system.
-System is something that performs a function.
• A use case is a model of the interaction between
External users of a software product (actors) and The
software product itself
• More precisely, an actor is a user playing a specific role
describing a set of user scenarios capturing user
requirements contract between end user and software
developers
Use Case Diagrams

17. Use-Case Diagrams
• Actors: A role that a user plays with respect to the system, including
human users and other systems. e.g., inanimate physical objects (e.g.
robot); an external system that needs some information from the
current system.
• Use case: A set of scenarios that describing an interaction between a
user and a system, including alternatives.
• System boundary: rectangle diagram representing the boundary
between the actors and the system.
• Association: Communication between an actor and a use case;
Represented by a solid line.

18. Actors
Actors
Could be human beings, other systems, timers
and clocks or hardware devices.
Actors that stimulate the system and are the
initiators of events are called primary actors
(active)
Actors that only receive stimuli from the system
are called secondary actors (passive)

19. Actors
Actors
Who/what will be interested in the system?
Who/what will want to change the data in the
system?
Who/what will want to interface with the system?
Who/what will want information from the
system?

21. • Use case is a particular activity a user can do
on the system.
• Is represented by an ellipse.
• Following are two use cases for a library
system.
Use Case Diagrams – Use Cases
ReserveBorrow

23. Construct Description Notation
Use-case A sequence of transactions performed
by a system that produces a measurable
result for a particular actor
Actor A coherent set of roles that users play
when interacting with these use cases
System
Boundary
The boundary between the physical
system and the actors who interact with
the physical system
23
Summary of Notations

24. 2. Use Case Diagram
• General form of Use Case Diagram

27. Use-Case Diagram: Example
Actor
Association System boundary
Use-case
System name

28. Use Case Diagram – Example1 (Library)
A Library System.
client employee
supervisor
library system
borrw
reserve
Order title
Finepayment

29. Use Case Diagram for Student Assessment
Management System
Teacher
Student
Printing administrator
Grade system
Record
grades
View grades
Distribute
Report cards
Create
report card