This document discusses nested state diagrams and interaction modeling techniques. It addresses: 1. The use of submachine states and composite states to model nested states within a state diagram. 2. Interaction modeling approaches including use cases, sequence diagrams, and activity diagrams. 3. Guidelines for developing use cases, sequence diagrams, and activity diagrams to fully capture system behavior.

1. Nested state Diagrams: its having few problems
1. Problem with flat state diagram: cant sow processing
within the processing (state diagram inside the state
diagram)
2. Expanding State: Expanding state diagram with additional
states diagram called Submachine.
Submachine: It is a state diagram that may be invoked as part of
another state diagram.
Nested States: A state inside the state.
Composite state: The Composite state name labels the outer
contour that Entirely encloses the nested state.
Active State is a composite state with regard to nested states.
Advanced State Modeling

2. Idle
Disconnected
TimeOut
do/ Sound Beep
Dial Tone
do/ check con.
Dialing
Connecting
Ringing
Connected
Warning
Do/ Play Msg
Recorded Msg
do/ play msg
Busy Tone
do/ selected
busy tone
ACTIVE
Phone Line
Repeat
Nested States for Phone line

3. REVERSENEUTRAL
FORWARD
Car Transmission Nested States for Phone line
SSECONDFIRST THIRD FOURTH
reverse
Push neutral
up up up
downdowndown
up down
Concurrency: Objects are Autonomous entities that can
ACT and CHANGE state independent of one another.
But sometime Object are also DEPENDANT on another Object
causes corresponding state changed.
Aggregation Concurrency: also called “and relationship”
The Aggregate states: corresponds to the combined states of all the parts.
A State diagram for an assembly is a collection of state diagrams.

4. REVERSENEUTRAL
FORWARD
TRANSMISSION Nested States for Phone line
SSECONDFIRST THIRD FOURTH
reverse
Push neutral
up up up
downdowndown
up down
CAR
BRAKESACCELERATIONTRANSMISSIONIGNITION
STARTING
IGNITION
ONOFF

5. Relation of class and State Model:
• State model describe the Behavior of the objects of given class
• State structure is related to and constrained by class structure.
• A object may have different state over time.
• A composite state is the aggregation of more than one concurrent
sub state.
• Three source of concurrency:
• First is aggregation of objects
• Aggregation within an object
• Concurrent behavior of object
• State model of a class is inherited by its subclasses
• The subclasses inherit both the states of the ancestor and the
transitions
• The signal hierarchy is independent of the class hierarchy
• States are defined by classes and objects
• Signals are more fundamental than states and more parallel to
classes.

6. Interaction Modeling
Structural Model : Class and Object diagrams
Behavioral Model : State Diagrams
Interaction Model : Use Cases/sequence/activity dig.
But for Full Behavior : State + Interaction diagrams.
Use Cases (Interaction Diagrams):
1. Use cases help to capture the informal requirements.
2. The interaction modeling is the third leg of modeling.
3. Describe how object interact to produce useful result.
4. Interaction can be modeled at different level of
abstraction.
5. Use cases explain how system interacts with outside actor

7. Sequence Diagram:
• It provide more detail and show the message exchanged among a
set of objects over time.
• Message include both asynchronous signal and procedure calls.
• Sequence Diagrams are good for showing the behavior sequence
seen by users of a system.
Activity Diagram:
• It provide further details and show the flow of control among the
steps of executions/ Computation.
• It show both Data Flow and Control flow.
• It Documents the all necessary steps to implements an operation or
a business process referenced in a sequence diagrams.
Actor:
An Actor is a direct external user of a system- an object or set of
objects that communicates directly with the system but that is not a
part of system.

8. Use Cases:
• A use cases is a coherent piece of functionality that a system can provide by
interacting with actors.
• A use cases involves the sequence of message among the system and its
actors.
• Some use cases have fixed sequence of message.
• Error conditions are also part of use cases.
• A use cases bring together all the behavior relevant to a slice of system
functionality.
• Use cases may partition the functionality of the system.
Use Cases Diagram:
Forms Table Schema

9. Guidelines for Use Case Model:
1. First determine the System boundary: identify cases and
users
2. Ensure that actors are focused: Actors implement as per
their work not by their no.
3. Each Use Case must provide value to users: represent
complete functionality, Interaction and Transaction.
4. Relate Use Cases and Actors: Must have at least one
Actor in Use Cases and each actor must have to participate
in Use Cases.
5. Remember that Use Case are informal: implements user
point of view.
6. Use Case can be Structured: smaller fragments using
relationship.

10. Sequence Model:
Scenario: it is a sequence of events that occurs during one
particular execution of a system such as for a use cases. Eg. User
authentication process
Sequence Diagram: shows the
• participants in interactions
• Sequence of message among them.
Sequence Diagram show the interaction of a system with the actors to
perform all or part of use case.
Each Actor as well as system is represented by a Vertical line called
LIFELINE and each Message by Horizontal Arrow from sender to
receiver.
Guidelines for Sequence Model:
1. Prepare at least one scenario per use case.
2. Abstract the scenario into sequence diagram
3. Divide complex interactions
4. Prepare a sequence diagrams for each error conditions.

11. Customer Broker NSE/BSE
Log In
Secure Communication
Display portfolio
Enter purchase Data
Request Confirmation
Confirm Order
Place Order
Display order no / info
Log Out
Report Result to Trade
Display Goods bought
Sequence diagram for share Trading/online stock broker

12. Activity Models: shows the
• Sequence of steps that makes up a complex process such as
algorithms or workflow.
• Show steps of computation or processing steps
• Shows data flow and control flow. (business flow)
An activity diagram is like a traditional flowchart in that it shows the
flows of control from steps to steps.
1. Activities: the steps of activity diagrams are
Operations/Computations. The purpose of activity diagram is to
show the steps within a complex process and sequence constraints
among them.
2. Branches: if there is more than one successor to an activity then
each arrow may be labeled with a condition in square brackets
(called Branches)
3. Initiation and Termination: A solid circle with outgoing arrow
shows starting point and Bull Eyes shows end points.
4. Executable activity: transfer of control during execution
5. Concurrent activity: computer separately but deliver at same time

13. Verify order
Execute order
Debit Account
Settle Account
Close Order
Send
confirmation
Update
Portfolio
Send failure
notice
[Success]
[Failure]
Activity
diagram for
online trade
processing

14. Find Seller at
Market Price
Find buyer at
Market price
Find buyer at
limit price or
better
Find seller at
limit price or
better
[Market Order]
[Buying][Selling]
[Selling] [Buying]
[Price availability]
[Limit order]
[Timeout]
[Price not available]
[order still active]

15. Guidelines for Activity Diagram:
1. Don’t misuse activity diagrams: develop use it to study
the algorithms and workflow
2. Level diagrams: should shows level of Execution
(Preprocessing/processing/Post Processing)
3. Careful about branches and conditions
4. Careful about Concurrent activities
5. Consider executable activity diagrams

16. Use cases Relationship:
Include Relationship: It incorporate (bind) one use cases within
the behavior sequence of another use cases.
An include use case is also like SUBROUTINE.
Extend Relationship: It adds incremental behavior to use case.
Secure
Session
Edit
Password
Update
Password
Trade Stock
Intraday Delivery
Future/
Option
<<include>>
<<include>>
<<extend>>
<<extend>>
<<extend>>

17. Use cases Relationship:
Generalization: It show specific variations on a general use case. It
convert analogous to Generalization among classes.
Parent use case represents general behavior and child use case extend
the parent one.
Guidelines for use case relationship:
1. Use case Generalization:
2. Use case Inclusion
3. Use case Extension
4. Include relationship vs. extend Relationship
Make Trade
Trade
Bonds
Trade
Stocks
Commodity

18. Make Trade
Trade
Bonds
Trade
Stocks
Commodity
Intraday Delivery
Future/
Option
<<extend>>
<<extend>>
<<extend>>
Secure
Session
Edit
Password
Update
Password
<<include>> <<include>>
Customer NSE/BSE
Stock Brokerage System
Combination of Use Case Relationship

19. Procedural sequence Model:
Sequence Diagrams with Passive Objects:
• All objects are not active.
• Most objects are passive and do not have their own threads of control
• A passive objects is not activated until it has been called.
• Once execution of an object complete and control returns to the caller
then the passive object becomes inactive.
Waiter Kitchen Table Bill Table
Kitchen Service
Food
Customer Order
Calculate Bill
Bill and Payments Slip
Food & Bill

20. Activation / Focus of Control:
The period of time for an object execution as a thin rectangle. This is
called the Activation or Focus of Control.
Lifeline:
The entire period during which the object exist is called Lifeline
Sequence Diagrams with Transient Objects:
Object A Object B
Object C
Compute E(c, d)
Final Result
Result
Create C (arg)
Operation E(m, n)

21. Guidelines for procedural Sequence Models:
1. Active vs Passive Objects
2. Advanced Features
Special Constructs for Activity Models:
Sending and receiving Signals:
Boot Sequence
User Login
Wait for response
Ready
Network
Request Validation
Receive confir.

22. Swimlanes: Make sufficient Partition of activities among Organizations.
Object Flows:
• If there is object flow then there is no meaning to draw control flow.
• Objects passes through several states during execution so object flow
is essential sometime.
• If object have state name then both control flow and propagation of
object from state to state is shown by activity diagram.
Flight Attendant Ground staff Catering
Clean
floor
Add
fuel
Load
foods
CAR Arrive CAR Stop
Activity diagram with Object Flow
Activity diagram with Swimlanes