1. Subject Name: Object oriented Modeling and Design
Subject Code: 10MCA51
Prepared By: Supriya.N.S
Department: MCA
Date:26/08/14
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2. 3.3 Signal Generalization 3.4 Concurrency 3.5 A Sample State Model
UNIT 3- Advanced State Modeling, Interaction Modeling and Advanced Interaction Modeling
3.1 Nested State Diagrams 
3.2 Nested States 
3.3 Signal Generalization 
3.4 Concurrency 
3.5 A Sample State Model
3.6 Use Case Models
3.7 Sequence Models
3.8 Activity Models
3.9 Use Case Relationships
3.10 Procedural Sequence Models
3.11 Special Constructs for Activity Models
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3. 3.1 Nested State Diagrams 3.1.1 Problems with Flat state diagram
The state diagrams are sufficient for describing basic systems but need additional things to handle large problems. E.g.: Consider an object with ‘Z’ independent Boolean attributes that affect control. Representing such an object with a single flat state diagram would require 2z states. For partitioning the state into n independent state diagrams, only 2z states are required.
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4. Expanding States: One way to organize a model is by having a high-level diagram with sub diagrams expanding certain states
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Figure-3.1: Vending Machine State Diagram

5. 3.2 Nested States
Second alternative for structuring states is using nested states. UML2 avoids using generalization in conjunction with states. Local state can be replaced with “nested states”.
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Figure 3.2: Nested States for Phone line

6. 3.3 Signal Generalization
Signals can be organized into a generalization hierarchy with inheritance of signal attributes. It permits different levels of abstraction to be used in a model
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FIGURE 3. 3: GENERALIZATION OF SIGNALS

7. 3.4 Concurrency
The State Model Supports different types of concurrency.
3.4.1 Aggregation Concurrency
3.4.2 Concurrency within an Object
3.4.3 Synchronization of Concurrent Activities
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8. 3.4.1 Aggregation Concurrency
The aggregate state corresponds to the combined states of all the parts. Aggregation is the “and-relationship”. Transitions for one object can depend on another object being in a given state.
3.4.2 Concurrency within an Object
You can partition some objects into subsets of attributes or links, each of which has its own sub diagram. The state of the object comprises one state from each sub diagram.
3.4.3 Synchronization of Concurrent Activities
The object does not synchronize the internal steps of the activities but must complete both activities before it can progress to its next state. 
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9. FIGURE 3.4: An Aggregation & its concurrent state diagram
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FIGURE 3.4: An Aggregation & its concurrent state diagram

10. Figure 3.5: Bridge game with concurrent states
Figure 3.6: Synchronization of control
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11. Figure 3.7: Thermostat User Interface
3.5 A SAMPLE STATE MODEL
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Figure 3.7: Thermostat User Interface

12. 3.6 Interaction Modeling 3.6.1 Use Case Models 3.6.2 Sequence Models
3.6.3 Activity Models
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13. 3.6 Use Case Models 3.6.1 What is Use Case Models?
The interaction model describes how the objects interact. Behavior of the system is needed to be described by State model and Interaction model. Use cases are helpful for capturing informal requirements. Sequence diagrams are good for showing the behavior sequences seen by users of a system. Activity diagrams can show data flows as well as control flows.
Use case Models contains:
Actors: An actor is a direct external user of a system
Use cases: A use case is a coherent piece of functionality that a system can provide by interacting with actors
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14. Figure 3.8: Use Case Model for Enrolment
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15. 3.6.2 Guidelines for Use case Models First determine the system
Ensure that actors are focused
Each use case must provide value to users.
Relate use cases and actors
Remember that use cases are informal
Use cases can be structured
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16. 3.7 Sequence Models
The sequence model elaborates the themes of use cases.
Two kinds of sequence models: 
scenarios
more structured format called sequence diagrams
3.7.1 Scenarios
A scenario is a sequence of events that occurs during one particular execution of a system, such as for a use case. A scenario can be displayed as a list of text statement.
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17. Scenario for a session with an online stock broker
Marie logs in
System establishes secure communications  
System displays portfolio information
Marie enters a buy order for 100 shares of GE at the market price  
System verifies sufficient funds for purchase
System displays confirmation screen with estimated cost  
Marie confirms purchase
System places order on securities exchange  
System displays transaction tracking number
Marie logs out
System establishes insecure communications
 System displays good-bye screen
System exchange reports results of trade
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18. Prepare one sequence diagram for each major flow of control
3.7.2 Sequence Diagrams
A sequence diagram shows the participants in an interaction and the sequence of messages among them. Each actor as well as the system is represented by a vertical line called a lifeline and each message by a horizontal arrow from the sender to the receiver.
Each use case requires one or more sequence diagrams to describe its behavior.
Prepare one sequence diagram for each major flow of control
Draw a separate sequence diagram for each task.
Prepare a sequence diagram for each exception condition within the use case
Try to elaborate all the use cases and cover the basic kinds of behavior with sequence diagrams
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19. Figure 3.9: Sequence Diagram for Website
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20. Figure 3.10: Sequence Diagram for Login
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21. Figure 3.11: Sequence Diagram for Login
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22. 3.7.3 Guidelines for Sequence Models
Prepare at least one scenario per use case
Abstract the scenarios into sequence diagrams
Divide complex interactions
Prepare a sequence diagram for each error condition
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23. 3.8 Activity Models
An activity diagram shows the sequence of steps that make up a complex process, but focuses on operations rather than on objects. Activity diagrams are most useful during the early stages of designing algorithms and workflows.
Activities
The steps of an activity diagram are operations, specifically activities from the state model.
Executable Activity Diagrams
An activity token can be placed on an activity symbol to indicate that it is executing. Multiple tokens can arise through concurrency.
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24. Figure 3.12: Activity diagram for Login
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25. Figure 3.13: Activity diagram for Stock trade processing
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26. Figure 3.14: Activity diagram for execute order.
3.8.1 Activities
The steps of an activity diagram are operations, specifically activities from the state model.
Figure 3.14: Activity diagram for execute order.
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27. 3.8.2 Executable Activity Diagrams
An activity token can be placed on an activity symbol to indicate that it is executing. Multiple tokens can arise through concurrency.
3.8.3 Guidelines for Activity Models
Don’t misuse activity diagrams.
Activity diagrams are intended to elaborate use case should not be used as an excuse to develop software via flowcharts.
Level diagrams
Consider executable activity diagrams
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28. 3.9 Use Case Relationships
Use cases can be structured for large applications. Complex use cases can be built from smaller pieces with the following relationships:
Include
Extend
Generalization
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29. The keyword <<include>> annotates the arrow
3.9.1 Include Relationship
The include relationship incorporates one use case within the behavior sequence of another use case
The UML notation for an include relationship is a dashed arrow from the source use case to the target (included) use case
The keyword <<include>> annotates the arrow
A use case can also be inserted within a textual description with the notation include use-case-name.
Factoring a use case into pieces is appropriate when the pieces represent significant behavior units.
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30. Figure 3.15 Use case inclusion
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31. The extend relationship adds incremental behavior to a use case
It represents the frequent situation in which some initial capability is defined, and later features are added modularly
Example
A stock brokerage system might have the base use case trade stocks, which permits a customer to purchase stocks for cash on hand in the account.
The additional behavior is inserted at the point where the purchase cost is checked against the account balance.
The UML notation for extend relationship is a dashed arrow from the extension use case to the base use case
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32. 3.16 Use case extension
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33. 3.9.3 Generalization
Generalization can show specific variations on a general use case, analogous to generalization among classes
The UML indicates generalization by an arrow with its tail on the child use case and a triangular arrowhead on the parent use case, the same notation that is used for classes
3.17 Use case extension
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34. 3.9.4 Combinations of Use case Relationships
A single diagram may combine several kinds of use case relationships
3.18 Use case Relationship
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35. 3.9.5 Guidelines for Use case Relationships
Use case generalization
Use case inclusion
Use case extension
Include relationship vs. extend relationship
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36. 3.10 Procedural Sequence Models
The UML has elaborations for sequence diagrams to show procedure calls.
Sequence Diagrams with Passive Objects
Most objects are passive and do not have their own threads of control. Activation shows the time period during which a call of a method is being processed, including the time when the called method has invoked another operation.
3.19 Sequence Diagrams with Passive Objects
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37. Figure 3.20 Sequence Diagrams with Transient Objects
ObjectA is an active object that initiates an operation. The notation for a call is an arrow from the calling activation created by the call. Activation, therefore, has a call arrow coming into its top and a return arrow leaving its bottom. If an object does not exist at the beginning of a sequence diagram, then it must be created during the sequence diagram.
Figure Sequence Diagrams with Transient Objects
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38. 3.11 Special Constructs for Activity Models
Sending & Receiving Signals: The UML shows the sending of a signal as a convex pentagon & Receiving of a signal as a concave signal.
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Figure 3.21 Activity diagram with signals

39. Figure: 3.22Activity diagram with swimlanes.
In a business model, it is often useful to know which human
organization is responsible for an activity.
Example: Sales, finance, marketing, and purchasing
It is sufficient to partition the activities among organizations.
Lines across swimlane boundaries indicate interactions among different organizations.
Figure: 3.22Activity diagram with swimlanes.
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40. Figure 3.23 Activity diagram with object flows.
It is helpful to see the relationships between an operation and the objects that are its argument values or results. An input or output arrow implies a control flow. Frequently the same object goes through several states during the execution of any activity diagram.UML shows an object value in a particular state by placing the state name in square brackets following the object name .
Figure 3.23 Activity diagram with object flows.
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