31081831 Airline Reservation System

DECCAN COLLAGE OF ENGINEERING & TECHNOLOGY Dar-us-Salam, Hyderabad -500 001.

DEPARTMENT OF INFORMATIN TECHNOLOGY

OBJECT ORIENTED SYSTEM DEVELOPMENT LAB

CERTIFICATE This is to certify that Of B.E. (III/IV) – 2nd SEMESTER, IT branch has successfully completed the MINI PROJECT work during the academic year 2010.

H.O.D

Internal Examiner

INDEX 1

External

S.no 1 2

3 4 5

Contents

Page no

Abstract Problem statement Proposed system SRS of ATM About UML

3 4 5 6 12

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CLASS DIAGRAM

47

7

USE CASE DIAGRAM

48

8

SEQUENCE DIAGRAM

51

9

COLLABORATION DIAGRAM

52

10

ACTIVITY DIAGRAM

53

11

SWIMLANE DIAGRAM

56

12

STATE CHART DIAGRAM

57

13

COMPONENT DIAGRAM

58

14

DEPLOYMENT DIAGRAM

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ABSTRACT 2

The online reservation system is basically derived from the GDS (global distribution system) also known as CRS (computer reservation system). The online reservation system has its database centrally located which is accessed through an Application Programming Interface (API).With the invent of online reservation system the traveller and the airline got the freedom to book a seat anywhere at anytime at their conveniance. The traveller can book a ticket at a click of a mouse saving the time and money for the traveller. It has also become a hassle free transaction for both the airline and the travller. The online reservation system involves three main actors the database , online operator and a databse scheduler. The database scheduler updates the database , te online operator accepts and confirms the booking and updates the database.

PROBLEM STATEMENT 3

The existing airline reservation system has many shortcomings associated with it. In the existing system airlines used to set flight reservation levels higher than seating capacity to compensate for passenger cancellations and no-shows accounting to overbooking in the system. If a traveller had to make / cancel reservation he had to visit either the airline or travel agent frequently to do so thus wasting time and money for all. In the existing system due to non-availability of a central server the airline and the agents suffered unwanted delays in bookings and payments. In the existing system integration of different airlines on a single platforms was not met. With the advent of the online reservation system these flaws can be overcome.

Proposed statement 4

The new online reservation system maintains the database centrally giving the clients the information required from anywhere in the world whenever required. This system requires the use of an API (Application Programming Interface) through which it extracts the data from a central database. The central database monitors all the data changes that are made at the client side to it and updates it automatically. Through online reservation system customer is able to book & purchase the ticket from his home/office conveniently it doesn’t require the customer to go to the airline or an agent to purchase a ticket thus saving time & money for the customer and an airline/agent. As the information is stored centrally the customer never loses his ticket as in the existing system.

SOFTWARE REQUIREMENTS SPECIFICATION AIRLINE RESERVATION SYSTEM 5

1. INTRODUCTION 1.1. PURPOSE The main purpose of this software is to reduce the manual errors involved in the airline reservation process and make it convenient for the customers to book the flights as when they require such that they can utilize this software to make reservations, modify reservations or cancel a particular reservation.

1.2 SCOPE The name of the software is “AIRLINE RESERVATION SYSTEM”. This software provides options for viewing different flights available with different timings for a particular date and provides customers with the facility to book a ticket, modify or cancel a particular reservation but it does not provide the customers with details of cost of the ticket and it does not allow the customer to modify a particular part of his reservation and he/she can modify all his details.

1.3 DEFINITIONS, ACRONYMS AND ABBREVIATIONS ARS-Airline Reservation System LAN-Local Area Network GUI-Graphical User Interface OS-Operating System RAM-Random Access Memory MB-Mega Bytes GB-Giga Bytes Mbps-Mega bits per second HDD-Hard Disk Drive

1.4 REFERENCES en.wikipedia.org/wiki/Airline_Reservations_System www.fyxm.net/airline-reservation-system-project-54574.htm www.ece.cmu.edu/~ece841/team2/index.html

1.5 OVERVIEW The rest of the document deals about all the main features of this software each will its purpose and its main functions. It also gives details about the interface with other products and related functionality of each product.

2. OVERALL DESCRIPTION

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2.1 PRODUCT PERSPECTIVE The “ARS” software is an independent application. It is a self-contained product. The system interfaces, user interfaces and hardware interfaces related with this software are defined as follows.

2.1.1 System Interfaces The client systems should be able to share the data available in the data base through the network connection.

2.1.2 User Interfaces The screen formats and menu structure should be in such a way that even have users will find it easy to use. The product must be use-friendly and very inter-active. The functionality provided by the system like displaying error messages should adapt itself to the different users of the software.

2.1.3 Hardware Interfaces Nil

2.1.4 Software Interfaces Name of the language: Visual Basics

2.1.5 Communication Interfaces There is an LAN used for communication among the different client systems to be used.

2.1.6 Memory Constraints The system would require disk space of 10 GB and a 256 MB HDD and 64 MB RAM for client systems.

2.1.7 Operation The users can first make a reservation in a particular flight for a particular date and time. The system provides the customer with a pin code which gives him access to either make any changes in his reservation or cancel a reservation. These must also be back up of data to enable any easy recovery from any features.

2.1.8 Site Adaptive Requirements The “ARS” software is an independent and self-contained product and no modification are required to adapt to a particular installation.

2.2 PRODUCT FUNCTIONS The major functions include • Providing flight details • Flight bookings for a particular destination, date and time and also providing with a pin code.

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• •

Allowing the customer to modify or cancel his reservation provided the correct pin code is given. Displaying a report of the number of people flying in a particular flight.

2.3 USER CHARACTERISTICS No technical experience is required basic knowledge of handling system is sufficient.

2.4 CONSTRAINTS • • • • • • • •

Regulatory policies: It is a mandatory that no text book must be left empty or contains insufficient data. Hardware limitations: There must be a 64 MB on board memory Control functions: The software must be very user-friendly and display appropriate error messages. Interfaces to other applications: Not applicable. Parallel operations: It must support many users simultaneously. Reliability requirements: Data redundancy and use of special/blank characters must be avoided. Safety/security considerations: The application must be exited always normally. Higher order language requirements: VB

2.5 ASSUMPTIONS AND DEPENDENCIES It is assumed that the details of the cost of ticket are already known to the customer. Future changes like providing different types of flights with different classes like business class, economic class will allow the customers to benefit from one facility.

2.6 APPORTIONING OF REQUIREMENTS The necessity of providing options to customer to choose their seat or to choose for economic or business class can be delayed until future versions of the software are developed.

3. SPECIFIC REQUIREMENTS 3.2 SOFTWARE PRODUCT FEATURES 3.2.1 FEATURE 1 The ability of the software is to provide the details of the flights available and allow the customers to choose a particular destination and make a reservation.

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3.2.1.1 PURPOSE The purpose of this is to enable the users to view the different flights available so as to make it convenient for him to make a reservation.

3.2.1.2 STIMULUS/RESPONSE Once the user chooses the particular option, the web pages corresponding to that are to be displayed on the screen i.e., it will display the different flights available to their respective destinations and allow the customer to book a ticket.

3.2.1.3 ASSOCIATED FUNCTIONAL REQUIREMENTS 3.2.1.3.1 FUNCTIONAL REQUIREMENTS Once the user makes a reservation, he must be provided with a pin code.

3.2.1.3.1.1 INTRODUCTION The user must be provided with the required information within 10 seconds.

3.2.1.3.1.2 INPUTS The user must enter the destination with date and timings and must make reservation by giving his personal details like name, address, age, gender, nationality.

3.2.1.3.1.3 PROCESSING Recognizing the correct details are entered that a message is displayed confirming his reservation and displays the pin code.

3.2.2 FEATURE 2 The software allows the user to modify an already existing reservation made by the customer if in case there are any changes that are to be modified in the reservations of the ticket.

3.2.2.1 PURPOSE The purpose is to allow the customer to make any changes in his personal details or flight booking details.

3.2.2.2 STIMULUS/RESPONSE Once the user requests for changing his reservation, it must be displayed on the screen prompting the customer to enter his pin code.

3.2.2.3 ASSOCIATED FUNCTIONALITY REQUIREMENTS 3.2.2.3.1 FUNCTIONAL REQUIREMENTS If the pin code provided by the customer does not match, then would notify the person by displaying error messages.

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3.2.2.3.1.1 INTRODUCTION The system will allow the customer to modify his reservation provided correct pin code has been entered by him.

3.2.2.3.1.2 INPUT The user should enter his pin code which gives him access to modify his reservation.

3.2.2.3.1.3 PROCESSING The pin code is processed and checked for his validity. If it is correct then the user can modify his reservation else an error message will be displayed asking the user to enter the correct pin code number.

3.2.2.3.1.4 OUTPUT Given the correct pin code, the user can now modify his reservation. A new pin code will be generated for the customers.

3.2.3 FEATURE 3 The software allows the user to cancel an already existing reservation made by the customer who has booked the ticket.

3.2.3.1 PURPOSE The purpose is to allow the customer to cancel his reservation if not required.

3.2.3.1 STIMULUS/RESPONSE Once the user requests for canceling his reservation, it must be displayed on the screen prompting the customer to enter his pin code.

3.2.3.3 ASSOCIATED FUNCTIONAL REQUIREMENTS 3.2.3.3.1 FUNCTIONAL REQUIREMENTS If the pin code provided by the customer does not match, then it would notify the person by displaying error messages.

3.2.3.3.1.1 INTRODUCTION The system will allow the customer to cancel his reservation provided correct pin code has been entered by the customer.

3.2.3.3.1.2 INPUT The user should enter his pin code which gives him access to cancel his reservation.

3.2.3.3.1.3 PROCESSING

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The pin code is processed and checked for its validity. If it is correct, then the user can cancel his reservation else an error message will be displayed asking the user to enter the correct pin code number.

3.2.3.3.1.4 OUTPUT Given the correct pin code, the user can now cancel his reservation.

UNIFIED MODELING LANGUAGE 11

Introduction: The unified modeling language(UML)is a standard language for writing software blue prints. The UML is a language for    

Visualizing Specifying Constructing Documenting

The artifacts of a software system: UML is a language that provides vocabulary and the rules for combing words in that vocabulary for the purpose of communication. A modeling language is a language whose vocabulary and rules focus on the concept and physical representation of a system. Vocabulary and rules of a language tell us how to create and real well formed models, but they don’t tell you what model you should create and when should create them.

VISUALIZING The UML is more than just a bunch of graphical symbols. In UML each symbol has well defined semantics. In this manner one developer can write a model in the UML and another developer or even another tools can interpret the model unambiguously. SPECIFYING UML is used fro specifying means building models that are precise, unambiguous and complete. UML addresses the specification of all the important analysis, design and implementation decisions that must be made in developing and deploying a software intensive system.

CONSTRUCTING UML is not a visual programming language but its models can be directly connected to a variety of programming languages. This means that it is possible to map from a model in the UML to a programming language such as java, c++ or Visual Basic or even to tables in a relational database or the persistent store of an object-oriented database. This mapping permits forward engineering. The generation of code from a UML model into a programming language. The reverse engineering is also possible you can reconstruct a model from an implementation back into the UML.

DOCUMENTING

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UML is a language for Documenting. A software organization produces all sorts of artifacts in addition to raw executable code. These artifacts include Requirements,Architecture,Design,Sourcecode,Project plans,Test,Prototype,Release. Such artifacts are not only the deliverables of a project,they are also critical in controlling,measuring and communicating about a system during its development and after its deployment. Conceptual model of the UML: To understand the UML, we need to form a conceptual model of the language and this requires learning three major elements. The UML Basic Building Blocks. The Rules that direct how those building blocks may be put together. Some common mechanisms that apply throughout the UML. As UML describes the real time systems it is very important to make a conceptual model and then proceed gradually. Conceptual model of UML can be mastered by learning the following three major elements:

UML building blocks Rules to connect the building blocks Common mechanisms of UML This chapter describes all the UML building blocks. The building blocks of UML can be defined as:  Things  Relationships  Diagrams

Things: Things are the most important building blocks of UML. Things can be:    

Structural Behavioral Grouping Annotational

Structural things: The Structural things define the static part of the model. They represent physical and conceptual elements. Following are the brief descriptions of the structural things.

Class:

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Class represents set of objects having similar responsibilities.

Interface: Interface defines a set of operations which specify the responsibility of a class.

Collaboration: Collaboration defines interaction between elements.

Use case: Use case represents a set of actions performed by a system for a specific goal.

Component: Component describes physical part of a system.

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Node: A node can be defined as a physical element that exists at run time.

Behavioral things: A behavioral thing consists of the dynamic parts of UML models. Following are the behavioral things: Interaction: Interaction is defined as a behavior that consists of a group of messages exchanged among elements to accomplish a specific task.

State machine: State machine is useful when the state of an object in its life cycle is important. It defines the sequence of states an object goes through in response to events. Events are external factors responsible for state change.

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Grouping things: Grouping things can be defined as a mechanism to group elements of a UML model together. There is only one grouping thing available. Package: Package is the only one grouping thing available for gathering structural and behavioral things.

Annotational things: Annotational things can be defined as a mechanism to capture remarks, descriptions, and comments of UML model elements. Note is the only one Annotational thing available. Note: A note is used to render comments, constraints etc of an UML element.

RELATIONSHIP IN UML Relationship is another most important building block of UML. It shows how elements are associated with each other and this association describes the functionality of an application. There are four kinds of relationships available. Dependency:

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Dependency is a relationship between two things in which change in one element also affects the other one.

Association: Association is basically a set of links that connects elements of an UML model. It also describes how many objects are taking part in that relationship.

Generalization: Generalization can be defined as a relationship which connects a specialized element with a generalized element. It basically describes inheritance relationship in the world of objects.

Realization: Realization can be defined as a relationship in which two elements are connected. One element describes some responsibility which is not implemented and the other one implements them. This relationship exists in case of interfaces.

UML DIAGRAMS: UML diagrams are the ultimate output of the entire discussion. All the elements, relationships are used to make a complete UML diagram and the diagram represents a system. The visual effect of the UML diagram is the most important part of the entire process. All the other elements are used to make it a complete one. UML includes the following nine diagrams and the details are described in the following chapters.  Class diagram  Object diagram 17

 Use case diagram  Sequence diagram  Collaboration diagram  Activity diagram  Statechart diagram  Deployment diagram  Component diagram  We would discuss all these diagrams in subsequent chapters of this tutorial.

ARCHITECTURE OF UML Any real world system is used by different users. The users can be developers, testers, business people, analysts and many more. So before designing a system the architecture is made with different perspectives in mind. The most important part is to visualize the system from different viewer.s perspective. The better we understand the better we make the system. UML plays an important role in defining different perspectives of a system. These perspectives are:    

Design Implementation Process Deployment

And the centre is the Use Case view which connects all these four. A Use case represents the functionality of the system. So the other perspectives are connected with use case. Design of a system consists of classes, interfaces and collaboration. UML provides class diagram, object diagram to support this. Implementation defines the components assembled together to make a complete physical system. UML component diagram is used to support implementation perspective. Process defines the flow of the system. So the same elements as used in Design are also used to support this perspective. Deployment represents the physical nodes of the system that forms the hardware. UML deployment diagram is used to support this perspective.

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CLASS DIAGRAM Overview: The class diagram is a static diagram. It represents the static view of an application. Class diagram is not only used for visualizing, describing and documenting different aspects of a system but also for constructing executable code of the software application. The class diagram describes the attributes and operations of a class and also the constraints imposed on the system. The class diagrams are widely used in the modelling of object oriented systems because they are the only UML diagrams which can be mapped directly with object oriented languages. The class diagram shows a collection of classes, interfaces, associations, collaborations and constraints. It is also known as a structural diagram.

Purpose: The purpose of the class diagram is to model the static view of an application. The class diagrams are the only diagrams which can be directly mapped with object oriented languages and thus widely used at the time of construction. The UML diagrams like activity diagram, sequence diagram can only give the sequence flow of the application but class diagram is a bit different. So it is the most popular UML diagram in the coder community. So the purpose of the class diagram can be summarized as:  Analysis and design of the static view of an application.  Describe responsibilities of a system.  Base for component and deployment diagrams.  Forward and reverse engineering.

How to draw Class Diagram? Class diagrams are the most popular UML diagrams used for construction of software applications. So it is very important to learn the drawing procedure of class diagram. Class diagrams have lot of properties to consider while drawing but here the diagram will be considered from a top level view. Class diagram is basically a graphical representation of the static view of the system and represents different aspects of the application. So a collection of class diagrams represent the whole system. The following points should be remembered while drawing a class diagram: The name of the class diagram should be meaningful to describe the aspect of the system. Each element and their relationships should be identified in advance. Responsibility (attributes and methods) of each class should be clearly identified. For each class minimum number of properties should be specified. Because unnecessary properties will make the diagram complicated. Use notes when ever required to describe some aspect of the diagram. Because at the end of the drawing it should be understandable to the developer/coder. 19

Finally, before making the final version, the diagram should be drawn on plain paper and rework as many times as possible to make it correct. Now the following diagram is an example of an Order System of an application. So it describes a particular aspect of the entire application. First of all Order and Customer are identified as the two elements of the system and they have a one to many relationship because a customer can have multiple orders. We would keep Order class is an abstract class and it has two concrete classes (inheritance relationship) SpecialOrder and NormalOrder. The two inherited classes have all the properties as the Order class. In addition they have additional functions like dispatch () and receive (). So the following class diagram has been drawn considering all the points mentioned above:

Where to use Class Diagrams? Class diagram is a static diagram and it is used to model static view of a system. The static view describes the vocabulary of the system. Class diagram is also considered as the foundation for component and deployment diagrams. Class diagrams are not only used to visualize the static view of the system but they are also used to construct the executable code for forward and reverse engineering of any system. Generally UML diagrams are not directly mapped with any object oriented programming languages but the class diagram is an exception. Class diagram clearly shows the mapping with object oriented languages like Java, C+ + etc. So from practical experience class diagram is generally used for construction purpose.  So in a brief, class diagrams are used for:  Describing the static view of the system.  Showing the collaboration among the elements of the static view.  Describing the functionalities performed by the system.  Construction of software applications using object oriented languages.

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OBJECT DIAGRAM Object diagram shows a set of objects and there relationships.Object diagram represents static snapshot of instances of the things found in class diagram. These diagrams addresses static design view or static process view of a system.

USE CASE DIAGRAM Overview: To model a system the most important aspect is to capture the dynamic behaviour. To clarify a bit in details, dynamic behaviour means the behaviour of the system when it is running /operating. So only static behaviour is not sufficient to model a system rather dynamic behaviour is more important than static behaviour. In UML there are five diagrams available to model dynamic nature and use case diagram is one of them. Now as we have to discuss that the use case diagram is dynamic in nature there should be some internal or external factors for making the interaction. These internal and external agents are known as actors. So use case diagrams are consists of actors, use cases and their relationships. The diagram is used to model the system/subsystem of an application. A single use case diagram captures a particular functionality of a system. So to model the entire system numbers of use case diagrams are used. Purpose: The purpose of use case diagram is to capture the dynamic aspect of a system. But this definition is too generic to describe the purpose. Because other four diagrams (activity, sequence, collaboration and Statechart) are also having the same purpose. So we will look into some specific purpose which will distinguish it from other four diagrams. Use case diagrams are used to gather the requirements of a system including internal and external influences. These requirements are mostly design requirements. So when a system is analyzed to gather its functionalities use cases are prepared and actors are identified. Now when the initial task is complete use case diagrams are modelled to present the outside view. So in brief, the purposes of use case diagrams can be as follows:  Used to gather requirements of a system.  Used to get an outside view of a system.  Identify external and internal factors influencing the system.  Show the interacting among the requirements are actors. How to draw Component Diagram?

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Use case diagrams are considered for high level requirement analysis of a system. So when the requirements of a system are analyzed the functionalities are captured in use cases. So we can say that uses cases are nothing but the system functionalities written in an organized manner. Now the second things which are relevant to the use cases are the actors. Actors can be defined as something that interacts with the system. The actors can be human user, some internal applications or may be some external applications. So in a brief when we are planning to draw an use case diagram we should have the following items identified. Functionalities to be represented as an use case Actors Relationships among the use cases and actors. Use case diagrams are drawn to capture the functional requirements of a system. So after identifying the above items we have to follow the following guidelines to draw an efficient use case diagram. The name of a use case is very important. So the name should be chosen in such a way so that it can identify the functionalities performed. Give a suitable name for actors. Show relationships and dependencies clearly in the diagram. Do not try to include all types of relationships. Because the main purpose of the diagram is to identify requirements. Use note when ever required to clarify some important points. The following is a sample use case diagram representing the order management system. So if we look into the diagram then we will find three use cases (Order, SpecialOrder and NormalOrder) and one actor which is customer. The SpecialOrder and NormalOrder use cases are extended from Order use case. So they have extends relationship. Another important point is to identify the system boundary which is shown in the picture. The actor Customer lies outside the system as it is an external user of the system.

INTERACTION DIAGRAM 22

We have two types of interaction diagrams in UML. One is sequence diagram and the other is a collaboration diagram. The sequence diagram captures the time sequence of message flow from one object to another and the collaboration diagram describes the organization of objects in a system taking part in the message flow. So the following things are to identified clearly before drawing the interaction diagram:  Objects taking part in the interaction.  Message flows among the objects.  The sequence in which the messages are flowing.  Object organization.  Following are two interaction diagrams modeling order management system. The first diagram is a sequence diagram and the second is a collaboration diagram. The Sequence Diagram: The sequence diagram is having four objects (Customer, Order, SpecialOrder and NormalOrder). The following diagram has shown the message sequence for SpecialOrder object and the same can be used in case of NormalOrder object. Now it is important to understand the time sequence of message flows. The message flow is nothing but a method call of an object. The first call is sendOrder () which is a method of Order object. The next call is confirm () which is a method of SpecialOrder object and the last call is Dispatch () which is a method of SpecialOrder object. So here the diagram is mainly describing the method calls from one object to another and this is also the actual scenario when the system is running.

The Collaboration Diagram: The second interaction diagram is collaboration diagram. It shows the object organization as shown below. Here in collaboration diagram the method call sequence is indicated by some numbering technique as shown below. The number indicates how

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the methods are called one after another. We have taken the same order management system to describe the collaboration diagram. The method calls are similar to that of a sequence diagram. But the difference is that the sequence diagram does not describe the object organization where as the collaboration diagram shows the object organization. Now to choose between these two diagrams the main emphasis is given on the type of requirement. If the time sequence is important then sequence diagram is used and if organization is required then collaboration diagram is used.

Where to use Interaction Diagrams? We have already discussed that interaction diagrams are used to describe dynamic nature of a system. Now we will look into the practical scenarios where these diagrams are used. To understand the practical application we need to understand the basic nature of sequence and collaboration diagram. The main purposes of both the diagrams are similar as they are used to capture the dynamic behaviour of a system. But the specific purposes are more important to clarify and understood. Sequence diagrams are used to capture the order of messages flowing from one object to another. And the collaboration diagrams are used to describe the structural organizations of the objects taking part in the interaction. A single diagram is not sufficient to describe the dynamic aspect of an entire system so a set of diagrams are used to capture is as a whole. The interaction diagrams are used when we want to understand the message flow and the structural organization. Now message flow means the sequence of control flow from one object to another and structural organization means the visual organization of the elements in a system. In a brief the following are the usages of interaction diagrams:    

To model flow of control by time sequence. To model flow of control by structural organizations. For forward engineering. For reverse engineering.

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STATE CHART DIAGRAM Overview: The name of the diagram itself clarifies the purpose of the diagram and other details. It describes different states of a component in a system. The states are specific to a component/object of a system. A Statechart diagram describes a state machine. Now to clarify it state machine can be defined as a machine which defines different states of an object and these states are controlled by external or internal events. Activity diagram explained in next chapter, is a special kind of a Statechart diagram. As Statechart diagram defines states it is used to model lifetime of an object. Purpose: Statechart diagram is one of the five UML diagrams used to model dynamic nature of a system. They define different states of an object during its lifetime. And these states are changed by events. So Statechart diagrams are useful to model reactive systems. Reactive systems can be defined as a system that responds to external or internal events. Statechart diagram describes the flow of control from one state to another state. States are defined as a condition in which an object exists and it changes when some event is triggered. So the most important purpose of Statechart diagram is to model life time of an object from creation to termination. Statechart diagrams are also used for forward and reverse engineering of a system. But the main purpose is to model reactive system. Following are the main purposes of using Statechart diagrams:    

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.

How to draw Component Diagram? Statechart diagram is used to describe the states of different objects in its life cycle. So the emphasis is given on the state changes upon some internal or external events. These states of objects are important to analyze and implement them accurately. Statechart diagrams are very important for describing the states. States can be identified as the condition of objects when a particular event occurs. Before drawing a Statechart diagram we must have clarified the following points:  Identify important objects to be analyzed.  Identify the states.  Identify the events. The following is an example of a Statechart diagram where the state of Order object is analyzed.

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The first state is an idle state from where the process starts. The next states are arrived for events like send request, confirm request, and dispatch order. These events are responsible for state changes of order object. During the life cycle of an object (here order object) it goes through the following states and there may be some abnormal exists also. This abnormal exit may occur due to some problem in the system. When the entire life cycle is complete it is considered as the complete transaction as mentioned below. The initial and final state of an object is also shown below.

Where to use Interaction Diagrams? From the above discussion we can define the practical applications of a Statechart diagram. Statechart diagrams are used to model dynamic aspect of a system like other four diagrams disused in this tutorial. But it has some distinguishing characteristics for modeling dynamic nature. Statechart diagram defines the states of a component and these state changes are dynamic in nature. So its specific purpose is to define state changes triggered by events. Events are internal or external factors influencing the system. Statechart diagrams are used to model states and also events operating on the system. When implementing a system it is very important to clarify different states of an object during its life time and statechart diagrams are used for this purpose. When these states and events are identified they are used to model it and these models are used during implementation of the system. If we look into the practical implementation of Statechart diagram then it is mainly used to analyze the object states influenced by events. This analysis is helpful to understand the system behaviour during its execution.

So the main usages can be described as:  To model object states of a system.

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 To model reactive system. Reactive system consists of reactive objects.  To identify events responsible for state changes.  Forward and reverse engineering.

ACTIVITY DIAGRAM Overview: Activity diagram is another important diagram in UML to describe dynamic aspects of the system. Activity diagram is 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. So the control flow is drawn from one operation to another. This flow can be sequential, branched or concurrent. Activity diagrams deals with all type of flow control by using different elements like fork, join etc.

Purpose: The basic purposes of activity diagrams are similar to other four diagrams. It captures the dynamic behaviour of the system. Other four diagrams are used to show the message flow from one object to another but activity diagram is used to show message flow from one activity to another. Activity is a particular operation of the system. Activity diagrams are not only used for visualizing dynamic nature of a system but they are also used to construct the executable system by using forward and reverse engineering techniques. The only missing thing in activity diagram is the message part. It does not show any message flow from one activity to another. Activity diagram is some time considered as the flow chart. Although the diagrams looks like a flow chart but it is not. It shows different flow like parallel, branched, concurrent and single. So the purposes can be described as: 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. How to draw Component Diagram? Activity diagrams are mainly used as a flow chart consists of activities performed by the system. But activity diagram are not exactly a flow chart as they have some additional capabilities. These additional capabilities include branching, parallel flow, swimlane etc. Before drawing an activity diagram we must have a clear understanding about the elements used in activity diagram. The main element of an activity diagram is the activity itself. An activity is a function performed by the system. After identifying the activities we need to understand how they are associated with constraints and conditions. So before drawing an activity diagram we should identify the following elements:  Activities  Association  Conditions  Constraints

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Once the above mentioned parameters are identified we need to make a mental layout of the entire flow. This mental layout is then transformed into an activity diagram. The following is an example of an activity diagram for order management system. In the diagram four activities are identified which are associated with conditions. One important point should be clearly understood that an activity diagram cannot be exactly matched with the code. The activity diagram is made to understand the flow of activities and mainly used by the business users. The following diagram is drawn with the four main activities:  Send order by the customer  Receipt of the order  Confirm order  Dispatch order After receiving the order request condition checks are performed to check if it is normal or special order. After the type of order is identified dispatch activity is performed and that is marked as the termination of the process.

Where to use Interaction Diagrams? The basic usage of activity diagram is similar to other four UML diagrams. The specific usage is to model the control flow from one activity to another. This control flow does not include messages. The activity diagram is suitable for modeling the activity flow of the system. An application can have multiple systems. Activity diagram also captures these systems and describes flow from one system to another. This specific usage is not available in other diagrams. These systems can be database, external queues or any other system. Now we will look into the practical applications of the activity diagram. From the above discussion it is clear that an activity diagram is drawn from a very high level. So it gives high level view of a system. This high level view is mainly for business users or any other person who is not a technical person.

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This diagram is used to model the activities which are nothing but business requirements. So the diagram has more impact on business understanding rather implementation details. Following are the main usages of activity diagram:  Modeling work flow by using activities.  Modeling business requirements.  High level understanding of the system's functionalities.  Investigate business requirements at a later stage.

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COMPONENT DIAGRAM Overview: Component diagrams are different in terms of nature and behaviour. Component diagrams are used to model physical aspects of a system. Now the question is what are these physical aspects? Physical aspects are the elements like executables, libraries, files, documents etc which resides in a node. So component diagrams are used to visualize the organization and relationships among components in a system. These diagrams are also used to make executable systems.

Purpose: Component diagram is a special kind of diagram in UML. The purpose is also different from all other diagrams discussed so far. It does not describe the functionality of the system but it describes the components used to make those functionalities. So from that point component diagrams are used to visualize the physical components in a system. These components are libraries, packages, files etc. Component diagrams can also be described as a static implementation view of a system. Static implementation represents the organization of the components at a particular moment. A single component diagram cannot represent the entire system but a collection of diagrams are used to represent the whole. So the purpose of the component diagram can be summarized as: Visualize the components of a system. Construct executables by using forward and reverse engineering. Describe the organization and relationships of the components. How to draw Component Diagram? Component diagrams are used to describe the physical artifacts of a system. This artifact includes files, executables, libraries etc. So the purpose of this diagram is different, Component diagrams are used during the implementation phase of an application. But it is prepared well in advance to visualize the implementation details. Initially the system is designed using different UML diagrams and then when the artifacts are ready component diagrams are used to get an idea of the implementation. This diagram is very important because without it the application cannot be implemented efficiently. A well prepared component diagram is also important for other aspects like application performance, maintenance etc. So 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.

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 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. The following is a component diagram for order management system. Here the artifacts are files. So the diagram shows the files in the application and their relationships. In actual the component diagram also contains dlls, libraries, folders etc. In the following diagram four files are identified and their relationships are produced. Component diagram cannot be matched directly with other UML diagrams discussed so far. Because it is drawn for completely different purpose. So the following component diagram has been drawn considering all the points mentioned above:

Where to use Component Diagrams? We have already described that component diagrams are used to visualize the static implementation view of a system. Component diagrams are special type of UML diagrams used for different purposes. These diagrams show the physical components of a system. To clarify it, we can say that component diagrams describe the organization of the components in a system. Organization can be further described as the location of the components in a system. These components are organized in a special way to meet the system requirements. As we have already discussed those components are libraries, files, executables etc. Now before implementing the application these components are to be organized. This component organization is also designed separately as a part of project execution. Component diagrams are very important from implementation perspective. So the implementation team of an application should have a proper knowledge of the component details. Now the usage of component diagrams can be described as:  Model the components of a system.  Model database schema.

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 Model executables of an application.  Model system's source code.

DEPLOYMENT DIAGRAM Overview: Deployment diagrams are used to visualize the topology of the physical components of a system where the software components are deployed. So deployment diagrams are used to describe the static deployment view of a system. Deployment diagrams consist of nodes and their relationships.

Purpose: The name Deployment itself describes the purpose of the diagram. Deployment diagrams are used for describing the hardware components where software components are deployed. Component diagrams and deployment diagrams are closely related. Component diagrams are used to describe the components and deployment diagrams shows how they are deployed in hardware. UML is mainly designed to focus on software artifacts of a system. But these two diagrams are special diagrams used to focus on software components and hardware components. So most of the UML diagrams are used to handle logical components but deployment diagrams are made to focus on hardware topology of a system. Deployment diagrams are used by the system engineers.  The purpose of deployment diagrams can be described as:  Visualize hardware topology of a system.  Describe the hardware components used to deploy software components.  Describe runtime processing nodes.

How to draw Component Diagram? Deployment diagram represents the deployment view of a system. It is related to the component diagram. Because the components are deployed using the deployment diagrams. A deployment diagram consists of nodes. Nodes are nothing but physical hardwares used to deploy the application. Deployment diagrams are useful for system engineers. An efficient deployment diagram is very important because it controls the following parameters  Performance  Scalability  Maintainability  Portability

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So before drawing a deployment diagram the following artifacts should be identified: Nodes Relationships among nodes The following deployment diagram is a sample to give an idea of the deployment view of order management system. Here we have shown nodes as:  Monitor  Modem  Caching server  Server The application is assumed to be a web based application which is deployed in a clustered environment using server 1, server 2 and server 3. The user is connecting to the application using internet. The control is flowing from the caching server to the clustered environment. So the following deployment diagram has been drawn considering all the points mentioned above:

Where to use Deployment Diagrams? Deployment diagrams are mainly used by system engineers. These diagrams are used to describe the physical components (hardwares), their distribution and association. To clarify it in details we can visualize deployment diagrams as the hardware components/nodes on which software components reside. Software applications are developed to model complex business processes. Only efficient software applications are not sufficient to meet business requirements. Business requirements can be described as to support increasing number of users, quick response time etc. To meet these types of requirements hardware components should be designed efficiently and in a cost effective way. Now a day's software applications are very complex in nature. Software applications can be stand alone, web based, distributed, mainframe based and many more. So it is very important to design the hardware components efficiently. So the usage of deployment diagrams can be described as follows:

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    

To model the hardware topology of a system. To model embedded system. To model hardware details for a client/server system. To model hardware details of a distributed application. Forward and reverse engineering.

UML NOTATIONS UML notations are the most important elements in modeling. Efficient and appropriate use of notations is very important for making a complete and meaningful model. The model is useless unless its purpose is depicted properly. So learning notations should be emphasized from the very beginning. Different notations are available for things and relationships. And the UML diagrams are made using the notations of things and relationships. Extensibility is another important feature which makes UML more powerful and flexible. The chapter describes the UML Basic Notations in more details. This is just an extension to the UML buildling block section I have discussed in previous chapter. Structural Things: Graphical notations used in structural things are the most widely used in UML. These are considered as the nouns of UML models. Following are the list of structural things. Classes  Interface  Collaboration  Use case  Active classes  Components  Nodes  Class Notation: UML class is represented by the diagram shown below. The diagram is divided into four parts.  The top section is used to name the class.  The second one is used to show the attributes of the class.  The third section is used to describe the operations performed by the class.  The fourth section is optional to show any additional components.

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Classes are used to represent objects. Objects can be anything having properties and responsibility. Object Notation: The object is represented in the same way as the class. The only difference is the name which is underlined as shown below..

As object is the actual implementation of a class which is known as the instance of a class. So it has the same usage as the class.

Interface Notation: Interface is represented by a circle as shown below. It has a name which is generally written below the circle.

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Interface is used to describe functionality without implementation. Interface is the just like a template where you define different functions not the implementation. When a class implements the interface it also implements the functionality as per the requirement. Collaboration Notation: Collaboration is represented by a dotted eclipse as shown below. It has a name written inside the eclipse.

Collaboration represents responsibilities. Generally responsibilities are in a group. Use case Notation: Use case is represented as an eclipse with a name inside it. It may contain additional responsibilities.

Use case is used to capture high level functionalities of a system. Actor Notation: An actor can be defined as some internal or external entity that interacts with the system.

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Actor is used in a use case diagram to describe the internal or external entities. Initial State Notation: Initial state is defined show the start of a process. This notation is used in almost all diagrams.

The usage of Initial State Notation is to show the starting point of a process. Final State Notation: Final state is used to show the end of a process. This notation is also used in almost all diagrams to describe the end.

The usage of Final State Notation is to show the termination point of a process. Active class Notation: Active class looks similar to a class with a solid border. Active class is generally used to describe concurrent behaviour of a system.

Active class is used to represent concurrency in a system. Component Notation: A component in UML is shown as below with a name inside. Additional elements can be added wherever required.

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Component is used to represent any part of a system for which UML diagrams are made.

Node Notation: A node in UML is represented by a square box as shown below with a name. A node represents a physical component of the system.

Node is used to represent physical part of a system like server, network etc. Behavioural Things: Dynamic parts are one of the most important elements in UML. UML has a set of powerful features to represent the dynamic part of software and non software systems. These features include interactions and state machines. Interactions can be of two types:  Sequential (Represented by sequence diagram)  Collaborative (Represented by collaboration diagram) Interaction Notation: Interaction is basically message exchange between two UML components. The following diagram represents different notations used in an interaction.

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Interaction is used to represent communication among the components of a system. State machine Notation: State machine describes the different states of a component in its life cycle. The notations are described in the following diagram.

State machine is used to describe different states of a system component. The state can be active, idle or any other depending upon the situation. Grouping Things:

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Organizing the UML models are one of the most important aspects of the design. In UML there is only one element available for grouping and that is package. Package Notation: Package notation is shown below and this is used to wrap the components of a system.

Annotational Things: In any diagram explanation of different elements and their functionalities are very important. So UML has notes notation to support this requirement. Note Notation: This notation is shown below and they are used to provide necessary information of a system.

Relationships A model is not complete unless the relationships between elements are described properly. The Relationship gives a proper meaning to an UML model. Following are the different types of relationships available in UML.  Dependency  Association  Generalization  Extensibility Dependency Notation: Dependency is an important aspect in UML elements. It describes the dependent elements and the direction of dependency. Dependency is represented by a dotted arrow as shown below. The arrow head represents the independent element and the other end the dependent element.

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Dependency is used to represent dependency between two elements of a system.

Association Notation: Association describes how the elements in an UML diagram are associated. In simple word it describes how many elements are taking part in an interaction. Association is represented by a dotted line with (without) arrows on both sides. The two ends represent two associated elements as shown below. The multiplicity is also mentioned at the ends (1, * etc) to show how many objects are associated.

Association is used to represent the relationship between two elements of a system. Generalization Notation: Generalization describes the inheritance relationship of the object oriented world. It is parent and child relationship. Generalization is represented by an arrow with hollow arrow head as shown below. One end represents the parent element and the other end child element.

Generalization is used to describe parent-child relationship of two elements of a system. Extensibility Notation:

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All the languages (programming or modeling) have some mechanism to extend its capabilities like syntax, semantics etc. UML is also having the following mechanisms to provide extensibility features. Stereotypes (Represents new elements) Tagged values (Represents new attributes) Constraints (Represents the boundaries)

Extensibility notations are used to enhance the power of the language. It is basically additional elements used to represent some extra behaviour of the system. These extra behaviours are not covered by the standard available notations.

Abstraction Relationship An abstraction relationship is a dependency between model elements that represents the same concept at different levels of abstraction or from different viewpoints. You can add abstraction relationships to a model in several diagrams, including use-case, class, and component diagrams.

Activity edges In activity diagrams, an activity edge is a relationship between two activity nodes that you can use to represent the control flow or object flow in an activity diagram. Aggregation relationships An aggregation relationship depicts a classifier as a part of, or as subordinate to, another classifier. Association relationships In UML models, an association is a relationship between two classifiers, such as classes or use cases, that describes the reasons for the relationship and the rules that govern the relationship. Binding relationships In UML models, a binding relationship is a relationship that assigns values to template parameters and generates a new model element from the template.

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Communication paths In UML modeling, a communication path is a type of association between nodes in a deployment diagram that shows how the nodes exchange messages and signals. Composition relationships A composition relationship, which was named composition association relationship in UML 1.4, represents whole–part relationships and is a form of aggregation. A composition relationship specifies that the lifetime of the part classifier is dependent on the lifetime of the whole classifier. Dependency relationships In UML modeling, a dependency relationship is a relationship in which changes to one model element (the supplier) impact another model element (the client). You can use dependency relationships in class diagrams, component diagrams, deployment diagrams, and use case diagrams. Deployment relationships In UML modeling, deployment relationships specify that a particular node type supports the deployment of an artifact type. Directed association relationships In UML models, directed association relationships are associations that are navigable in only one direction. Generalization relationships In UML modeling, a generalization relationship is a relationship in which one model element (the child) is based on another model element (the parent). Generalization relationships are used in class, component, deployment, and use case diagrams. Implementation relationships In UML modeling, an implementation relationship is a specialized type of realization relationship between a classifier and a provided interface. The implementation relationship specifies that the realizing classifier must conform to the contract that the provided interface specifies. Include relationships In UML modeling, an include relationship is a relationship in which one use case (the base use case) includes the functionality of another use case (the inclusion use case). The include relationship supports the reuse of functionality in a use case model. Manifestation relationships In UML modeling, a manifestation relationship shows which model elements, such as components or classes, are manifested in an artifact. The artifact manifests, or includes, a specific implementation for, the features of one or several physical software components. Realization relationships In UML modeling, a realization relationship is a relationship between two model elements, in which one model element (the client) realizes the behavior that the other model element (the supplier) specifies. Several clients can realize the behavior of a

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single supplier. You can use realization relationships in class diagrams and component diagrams. Usage relationships In UML modeling, a usage relationship is a type of dependency relationship in which one model element (the client) requires another model element (the supplier) for full implementation or operation.

Common Mechanisms In UML Specifications textual statement of syntax & semantics diagrams give view of specification

Adornments elements in UML - unique graphical notation adornments - added information about class

Common Divisions general property vs. specific instance class vs. object use case vs. use case instance UML syntax: underline name of instance separation of interface & implementation interface - contract implementation - concrete realization of contract

Extensibility Mechanisms stereotype allows creation of new kinds of building blocks from existing ones tagged value allows creation of new information in specification constraint allows addition of new rules & modification of existing rules

Rules Of UML  specify what model should look like  semantic rules for  names 44

        

scope visibility integrity execution Common properties of models elided - hide some elements for simplicity incomplete inconsistent rules of UML make it easier to address these problems

 TERMS AND CONCEPTS UML 2.2 has 14 types of diagrams divided into two categories.[10] Seven diagram types represent structural information, and the other seven represent general types of behavior, including four that represent different aspects of interactions. These diagrams can be categorized hierarchically as shown in the following class diagram: UML does not restrict UML element types to a certain diagram type. In general, every UML element may appear on almost all types of diagrams; this flexibility has been partially restricted in UML 2.0. UML profiles may define additional diagram types or extend existing diagrams with additional notations. In keeping with the tradition of engineering drawings, a comment or note explaining usage, constraint, or intent is allowed in a UML diagram.

Structure diagrams  Structure diagrams emphasize what things must be in the system being modeled:  Class diagram: the class diagrams describes the structure of a system by showing the system's classes, their attributes, and the relationships among the classes.  Component diagram: depicts how a software system is split up into components and shows the dependencies among these components.  Composite structure diagram: describes the internal structure of a class and the collaborations that this structure makes possible.  Deployment diagram: serves to model the hardware used in system implementations, and the execution environments and artifacts deployed on the hardware.  Object diagram: shows a complete or partial view of the structure of a modeled system at a specific time.  Package diagram: depicts how a system is split up into logical groupings by showing the dependencies among these groupings.  Profile diagram: operates at the metamodel level to show stereotypes as classes with the stereotype, and profiles as packages with the stereotype. The extension relation (solid line with closed, filled arrowhead) indicate what metamodel element a given stereotype is extending.

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Since structure diagrams represent the structure they are used extensively in documenting the architecture of software systems.

Behavior diagrams Behavior diagrams emphasize what must happen in the system being modeled:  Activity diagram: represents the business and operational step-by-step workflows of components in a system. An activity diagram shows the overall flow of control.  State machine diagram: standardized notation to describe many systems, from computer programs to business processes.  Use case diagram: shows the functionality provided by a system in terms of actors, their goals represented as use cases, and any dependencies among those use cases. Since behavior diagrams illustrate the behaviour of a system, they are used extensively to describe the functionality of software systems.

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CLASS DIAGRAM The class diagram describes the attributes and operations of a class and also the constraints imposed on the system. The class diagrams are widely used in the modelling of object oriented systems because they are the only UML diagrams which can be mapped directly with object oriented languages. The class diagram shows a collection of classes, interfaces, associations, collaborations and constraints. It is also known as a structural diagram.

Contents: Class diagrams commonly contain the following things  Classes  Interfaces  Collaborations  Dependency,generation and association relationships

Fig: Class Diagram

Class Diagram for Airline Reservation System

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Traveller Name Passport no. Telephone no. Address

Reservation incharge Incharge name incharge id inchrg location

Viewinfo() Booking() Payment() cancel_reservation() Date_change()

accept() reject() update database() manage payment()

Airline Database Airline name Date of update update time table() update cost info() update changes to database()

USE CASE DIAGRAM Use case diagrams are used to gather the requirements of a system including internal and external influences. These requirements are mostly design requirements. So when a system is analyzed to gather its functionalities use cases are prepared and actors are identified. Now when the initial task is complete use case diagrams are modelled to present the outside view. So in brief, the purposes of use case diagrams can be as follows:    

Used to gather requirements of a system. Used to get an outside view of a system. Identify external and internal factors influencing the system. Show the interacting among the requirements are actors.

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Search for flights

show avbl flights

select destination

Airline Reservation Database make reservation



traveller

pay money

purchase ticket accept request

cancel reservation

Reservation incharge

deny requestt



accept payment

Fig: Use Case Diagram

INTERACTION DIAGRAM That is why sequence and collaboration diagrams are used to capture dynamic nature but from a different angle. So the purposes of interaction diagram can be describes as:    

To capture dynamic behaviour of a system. To describe the message flow in the system. To describe structural organization of the objects. To describe interaction among objects.

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Fig:Sequence Diagram

Fig: Collaboration Diagram

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SEQUENCE DIAGRAM FOR CHANGING RESERVATION Traveller

: Booking System

1: change reservation

Reservation incharge

Airline reservation DB

2: Get customer details 3: get itineary

4: show itineray

5: select segment 6: present detailed info 7: select avbl flights 8: show avbl flights 9: payment 10: update database 11: generate report

Fig: Sequence Diagram

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COLLABORATION DIAGRAM FOR CHANGING RESERVATION

3 : g e t it in e a ry

9: pay m ent

R e s e rva tio n in c h a rg e

2 : G e t c u s to m e r d e t a ils

T ra ve lle r

1 : c h a n g e re s e rva t io1n1 : g e n e ra te re p o rt 5 : s e le c t s e g m e n t

4 : s h o w itin e ra y 6 : p re s e n t d e t a ile d in fo

: B o o k in g S y s te m

10: u pda te da taba s e 7 : s e le c t a vb l flig h t s

8 : s h o w a vb l flig h t s

A irlin e re s e rva t io n D B

Fig: Collaboration Diagram

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ACTIVITY DIAGRAM Activity diagram is another important diagram in UML to describe dynamic aspects of the system. Activity diagram is 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. So the control flow is drawn from one operation to another. This flow can be sequential, branched or concurrent. Activity diagrams deals with all type of flow control by using different elements like fork, join et

Branching A branch specifies alternate paths takes based on some Boolean expression Branch is represented by diamond Branch may have one incoming transition and two or more outgoing one on each outgoing transition,you place a Boolean expression shouldn’t overlap but they should cover all possibilities.

Forking and Joining Fork A fork represents the splitting of a single flow of control into two or more concurrent Flow of control. A fork may have one incoming transition and two or more outgoing transitions, each of which represents an independent flow of control. Below fork the activities associated with each of these path continues in parallel.

Join A join represents the synchronization of two or more concurrent flows of control. A join may have two or more incoming transition and one outgoing transition. Above the join the activities associated with each of these paths continues in parallel.

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Swimlane: Swimlanes are useful when we model workflows of business processes to partition the activity states on an activity diagram into groups. Each group representing the business organization responsible for those activities,these groups are called swimlanes.

ACTIVITY DIAGRAM FOR MAKING RESERVATION

Select Flight

Available

Not Available

Submit Request

Accepted

Rejected

Payment

View Report

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ACTIVITY DIAGRAM FOR CHANGING RESERVATION

Cancel Reservation

New reservation

Get Refunded

Select Flight

Submit Request

Accept

Reject

View Report

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SWIMLANE DIAGRAM FOR AIRLINE RESERVATION SYSTEM

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Trav eller

Reserv ation Incharge

Submit Request

Airline reserv ation database

View Retrieve data Review data

Reject

Accept

Store Data

Generate Report

View report

Payment

Store data Generate Receipt

Print Reciept

STATE CHART DIAGRAM A state chart diagrams a state machine, emphasizing the flow of control from state to state.

Contents

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State chart diagrams commonly contain  Simply state and composite states  Transitions, including events and actions

Common use They are use to model the dynamic aspects of a system. Event ordered behavior of any kind of objects, to model reactive objects.

ACTIVE Submitting Request

Processing Request

START

Generating Report EXIT

FIG. for the State diagram of Airline Reservation System

COMPONENT DIAGRAM Component diagrams are different in terms of nature and behaviour. Component diagrams are used to model physical aspects of a system.

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Now the question is what are these physical aspects? Physical aspects are the elements like executables, libraries, files, documents etc which resides in a node. So component diagrams are used to visualize the organization and relationships among components in a system. These diagrams are also used to make executable systems.

Fig: Component Diagram

Airline Resevation.exe

Airline Database

ARS.java .dll

.flv

doc

DEPLOYMENT DIAGRAM Deployment diagrams are used to visualize the topology of the physical components of a system where the software components are deployed. So deployment diagrams are used to describe the static deployment view of a system. Deployment diagrams consist of nodes and their relationships.

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Purpose: The name Deployment itself describes the purpose of the diagram. Deployment diagrams are used for describing the hardware components where software components are deployed. Component diagrams and deployment diagrams are closely related. Component diagrams are used to describe the components and deployment diagrams shows how they are deployed in hardware.

Fig: Deployment Diagram

DEPLOYMENT DIAGRAM FOR AIRLINE RESERVATION SYSTEM

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Airline Reservation Database

Reservation Incharge

Traveller 1

Traveller 2

Fig: Deployment Diagram

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Traveller n