Design of a Mobile Phone Backup System

Abstract

Mobile phones come in different shapes and sizes. Owners of GSM phones are sometimes classed by the type of phone(s) they own and the functionalities the phones can perform. The demand for functionalities that come with GSM phones has hence increased significantly. The major striking features that most users clamor for apart from the phone having digital camera/recording facilities is the ability of their phones to store more data – or at least have some sort of extended memory-, display a high level of security and provide for backup of phone data (in case of any mishap to the phone). As more and more functionalities are added to these phones, the more expensive they become. Hence these days, we find phones costing hundreds of thousands of naira. Not all can afford phones this expensive. Everyone wants to maximize and improve on what he already has. The average man looks for means by which he can extend the functionalities that come with his phone. This study examined how mobile phones work, designed graphical user interfaces, the application and the database used for the implementation. This designed application backs up mobile phone and SIM data (contacts and SMS) on the computer storage. It also allows for easy retrieval and restoration of the data to phone memory when the need arises. The objectives considered in the design included: user-friendly graphical user interface (GUI) for user interaction; modular subroutines, methods and functions that retrieves data from the phone and stores it on the computer memory; modular subroutines, methods and functions that retrieves data from the SIM and stores it on the computer memory; modular subroutines and functions that send data from the computer back to the phone; portable database for storing and retrieving the data.

Full text

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 21
Design of a Mobile Phone Backup System
Aregbesola M. K.1 and Osunade A. O.2
1 College of Information and Communication Technology, Salem University, Lokoja, Kogi State, Nigeria.
2 Department of Computer Science, University of Ibadan, Ibadan, Oyo State, Nigeria.
1 kennie747@yahoo.com, 2 seyiosunade@gmail.com.
Abstract
Mobile phones come in different shapes and sizes. Owners of GSM phones are sometimes classed by the type of phone(s)
they own and the functionalities the phones can perform. The demand for functionalities that come with GSM phones has
hence increased significantly. The major striking features that most users clamor for apart from the phone having digital
camera/recording facilities is the ability of their phones to store more data – or at least have some sort of extended memory - ,
display a high level of security and provide for backup of phone data (in case of any mishap to the phone). As more and more
functionalities are added to these phones, the more expensive they become. Hence these days, we find phones costing
hundreds of thousands of naira. Not all can afford phones this expensive. Everyone wants to maximize and improve on what
he already has. The average man looks for means by which he can extend the functionalities that come with his phone. This
study examined how mobile phones work, designed graphical user interfaces, the application and the database used for the
implementation. This designed application backs up mobile phone and SIM data (contacts and SMS) on the computer
storage. It also allows for easy retrieval and restoration of the data to phone memory when the need arises. The objectives
considered in the design included: user-friendly graphical user interface (GUI) for user interaction; modular subroutines,
methods and functions that retrieves data from the phone and stores it on the computer memory; modular subroutines,
methods and functions that retrieves data from the SIM and stores it on the computer memory; modular subroutines and
functions that send data from the computer back to the phone; portable database for storing and retrieving the data.
Keywords: Mobile Phone, Data Backup, System Design, K-Backup.
1. Introduction
Considering the prevalence of mobile phone misplacement and theft, this research was focused on trying to safeguard user
interest by making backups of mobile phone information. A brief insight into the typical device functionality was followed
by the system design of the data-backup application. The backup operation affects data stored on both the Subscribers
Identification Module (SIM) and the phone memory. The data is stored on the computer storage in such a way as to allow for
easy retrieval and restoration of the data to phone memory. User-friendly graphical user interface for user interaction,
modular subroutines, portable database for data storage were some of the features considered in the design. Several intuitive
system design tools were employed in the design to make the concept being discussed as lucid as possible. The context
diagram, data flow diagram, state diagram, use case diagram, deployment diagram, entity relation model and a number of
other UML tools were employed.
Mobile phones come in different shapes and sizes. Owners of GSM phones are sometimes classed by the type of phone(s)
they own and the functionalities the phones can perform. The demand for functionalities that come with GSM phones has
hence increased significantly. The major striking features that most users clamor for apart from the phone having digital
camera/recording facilities is the ability of their phones to store more data – or at least have some sort of extended memory - ,
display a high level of security and provide for backup of phone data (in case of any mishap to the phone). As more and more
functionalities are added to these phones, the more expensive they become. Hence these days, we find phones costing
hundreds of thousands of naira. Not all can afford phones this expensive. Everyone wants to maximize and improve on what
he already has. The average man is in search of a means by which he can extend the functionalities that port naturally with
his phone.
There is the risk of loosing all of ones contacts and valuable text messages in situations of Phone/SIM loss, damage, or
erasure by mistake due to careless use. It is hence very necessary to back up the data in the phonebook of a mobile
phone/SIM.

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 22
One can manually write out all these data from his phone. This would however be very time consuming and tedious. Besides,
it would be extremely difficult to keep this manual record up to date since the user will need to browse through the entire
contents of the phone each time he plans to make an update of his record.
It is for this reason that this data backup tool was designed and developed to automate the backup of mobile phone data.
Details of this software are discussed in subsequent chapters of this work.
2. Literature Review
In spite of its current popularity, mobile phones have existed long before GSM was conceived. In telecommunication, a
wireless phone, cellular mobile, cell phone or mobile phone, is a mobile communications system that uses a combination of
radio wave transmission and conventional telephone switching to permit telephone communication to and from mobile users
within a specified area.
The term does not comprise the so-called portable phone or cordless phone, which is associated with a fixed telephone
landline and can only be operated close to (less than 100 meters of) its base station, such as in and around the house. The
term cell phone applies specifically to mobile phones which use a cellular network; satellite phones are also mobile phones,
but not cellular (David, 1991; Feldmann and Rissen, 1993b).
In cellular mobile systems, large geographical areas are segmented into many smaller areas, i.e., cells, each of which has its
own radio transmitters and receivers and a single controller interconnected with the public switched telephone network. Each
cell site has a range of 3-5 miles and overlaps other cell sites. All of the cell sites are connected to one or more cellular
switching exchanges which can detect the strength of the signal received from the telephone. As the telephone user moves or
roams from one cell area to another, the exchange automatically switches the call to the cell site with the strongest signal
(David, 1991; Feldmann and Rissen, 1993b).
All cell phones have special codes associated with them. These codes are used to identify the phone, the phone's owner and
the service provider (Maduka, 2005). They are:
 Electronic Serial Number (ESN)
 Mobile Identification Number (MIN)
 System Identification Code (SID)
While the ESN is considered a permanent part of the phone, both the MIN and SID codes are programmed into the phone
when you purchase a service plan and have the phone activated (David, 1991; Feldmann and Rissen, 1993b).
3. Requirement Analysis and Design
A series of tools and methodologies were used in the design of the system. The overall system design, organizational flow
and database structure are clearly represented.
3.1 Analysis of Existing Systems
Most people that currently have a backup of there mobile phone data acquired these data manually from the phone. By
manually, it is meant that they scroll through the mobile phone and with the aid of a pen and several pieces of paper copy out
the data displayed on the Liquid Crystal Display (LCD). Many of the other existing systems are mere modifications of this
manual technique.
This technique obviously promises to be highly time consuming and stressful. Thus, most people would rather go without a
backup for the mobile phone data than go through the stress of backing up the data manually.
3.2 Requirement Analysis of the New System
The system after it has been developed must satisfy these requirements for it to be considered satisfactory. The analysis of the
requirements expected of the system to be developed is as follows:
The system to be developed must first and foremost be able to fully identify any mobile phone attatched to it. The system
should then be able to read the mobile phones phonebook which consist of contact names and their phone numbers, and
transfer them into the computer memory. It should also be able to read text messages received through the short message
service (SMS), and transfer them into the computer memory. The data read from the phone must be displayed for the user to
see, and saved only if the user chooses to do so. The data stored on the computer memory should be retrievable and readable
in the form of a phonebook and direct access list for both the contacts and text messages respectively. The user of the system
should be able to transfer these data stored on the computer unto a mobile phone when he wants to.

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 23
Other functionalities expected of the system is that it should be able to allow the user to send text messages from the system
to any network of his choice, using SMS offered by the subscriber’s network. The system should support multiple users.
3.3 Design of the New System
This section will be considering the design of the system using different design (Pfleeger, 2001) models to project the system
from different angles of view. The different models used will allow the entire system to be seen when they are read with
respect to the perspective represent. Naturally, different models are usually best suited to different views of a system under
development.
3.3.1 Context Diagram
It is used to represent pictorially, the scope and boundaries of the area under study. The purpose is to identify what is to be
included in the study. The area to be studied is shown as a single circle in the center of the diagram. The system is not
isolated but interacts with other entities which are shown as rectangles on the context diagram as shown in Fig. 1.
3.3.2 Data Flow Diagram (DFD)
It is a graphic representation of the system that shows data flows to, from and within the system, processing functions that
change the data in some manner, and the storage of the data. The data flow diagram can be used to represent systems at
different levels of depth. The level 0 (zero) data flow diagram as shown in Fig. 2 is the topmost level at which a system can
be represented and has the least complexity.
PHONE
BACKUP
SOFTWARE
USER
PHONE
SIM
SERVICE CENTER
Us
er Data, Text Messages
Register User, allow User
access and Confirmation
Phonebook and Text
Messages
Phonebook and Text
Messages
Phonebook
Phonebook
SMS and Calls
Fig. 1: The Context Diagram of the system

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 24
3.3.3 The Unified Modeling Language (UML) Design of the system
The Unified Modeling Language is a notational approach that is popular for describing object-oriented (OO) solutions. It can
be tailored to fit different development situations and software life cycles (Stevens and Pooley, 1999; Oestereich, 1999;
Bennett, McRobb and Farmer, 1999). UML can be used to visualize, specify, or document a problem. UML diagrams include
the dynamic view of the system, lists of activities, interactions, sequences, collaboration, and state diagrams. The UML
diagrams also show the static view of the system depicted by class, package and deployment diagrams.
3.3.3.1 The State Diagram
The state diagram as show in Fig 3 & 4 shows all possible states that an object can take. The change from one state to another
is triggered by a message (representing an event) that is sent from one object to another. It is usually necessary when a class
has many state changes (Stevens and Pooley, 1999; Oestereich, 1999).
PHONE
BACKUP
SYSTEM
SELECT
CONNECTION
DEVICE
USER
PHONE
SIM
CONVERT
BETWEEN
TEXT AND
PDU
TEXT MESSAGE
User data, Text and
Address
Register User, allow
user access and
confirmation
Phonebook
and Text
Phonebook
and Text
Phonebook
and Text
Phonebook
and Text
Phonebook
Phonebook
Text Messages
Text
Messages
SMS and
Address
SMS and
Address
SERVICE
CENTER
SMS and
Calls
Confirmation
COMPUTER
PHONE BOOK
Phonebook
Information
Phonebook
Information
Fig. 2: The level 0 data flow diagram (top level) for the system

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 25
3.3.3.3 The Use Case Diagram
The sequence diagram describes the set of sequence of actions including variants, that a system performs that yields an
observable result of value to a particular actor. A use case describes what a system (Subsystem, class, or interface) does, but
it does not specify how it does it. This use case represents a functional requirement of the system as a whole (Oestereich,
1999). See Fig. 5. The interactions among classes are illustrated using interaction diagrams. The interaction diagrams are of
two types; Sequence and Collaboration Diagrams.
Fig. 5: Use Case Diagram
Phone
User
Retrieve SMS
Retrieve Phonebook
Register
Backup SMS
Backup Phonebook
Network
Provider
Provide Network
Source of Phonebook
Source of SMS
Get SMS backup
Get Phonebook
backup
Computer
Store Phonebook backup
Store SMS backup
Send Phonebook backup
Send SMS backup
SYSTEM
Fig. 4: State Diagram for the System
Command
Mode
Text
Mode
[Activate text boxes text]
[Activate Command buttons]
[Edit text]
[Use command
bottons]
[Loose registration details]
[Has valid user name,
password, and reg. no.]
[Does not have valid user name,
password, or reg. no.]
UNREGISTERED
USER
REGISTERED
USER
[Register and get
registration number.]
Fig. 3: State Diagram for User Class

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 26
3.3.3.2 Class Diagram of the New System
The UML class diagrams are used to document the static structure of the system. That is, it shows the classes (McKelvy,
1996) being used and how they are related, but not how they interact to achieve particular behaviors. A class diagram also
shows other aspects of static structure such as packages (Stevens and Pooley, 1999). See Fig. 6.
0..*
0..1
1
TEXT MESSAGE
Collect ( )
Delete ( )
First ( )
Last ( )
Next ( )
Previous ( )
Delete ( )
DeleteAll ( )
SaveToPhone ( )
SaveAllToComputer ( )
SavItemToComputer ()
AddMessage ( )
NavigateTo ( )
BreakAndSave ( )
AcquirePhText: String
PHONEBOOK
AcquirePhText: String
BreakUpItemSave ( )
Delete ( )
AddEntry ()
Collect ( )
DeleteAll ( )
DeleteItem ( )
SaveItemToPhone ( )
SaveToItemComputer()
SaveAllToPhone()
SaveAllToComputer()
DATABASE
RegNo: Long
UserName: String
SaveItemToDatabase (Message,
PhoneNo, DateTime)
RegisterPerson (Name, Password)
SearchPerson (Name, Person, RegNo)
SaveAllToDataBase (NoSMS, Message,
Number, DateTime)
DeleteItemFromDatabase (Message,
Number, DateTime)
DeleteAllText ( )
DeleteCompPhoneItem (Name, PhoneNo)
DeleteAllPhoneNo ( )
RetrievePhonebook (MSFlex)
RetrieveTextMessage (MSFlex)
SMS
Inputs: String
SendSMS ( )
SaveSMS ( )
FLASH
PhoneNo: String
Flash ( )
Se
nd Encoded
Data
1
0..*
1
0..*
ENCODE
Encode(Address,
Sms):String
CovToHex(Deci): String
ByteSwap(TeleNo): Sting
EncodeUd(Inputs): String
Encoded: String
Se
nd Encoded
Data
USER
Name: String
Password: String
Reg. No: Long
Sets
0…*
0…*
0...*
CONTACT
RegNo: Long
SubcrName: String
PhoneNo: String
Names: String
Contacts (PhoAcquire,
MsFlex, Changer)
DECODE
SmsOriginNo: String
SmsDateTime
Decode(Inputs): String
HexToDeci(HexVal):
String
HexString (TxToConv):
String
ConvertHexToBin(HexVa
l): String
Sms7Bits(BinVal): String
GetSourceAdd(PhoNo,
SMS):String
DateTime(TimeInput)
Sends Data
1
PORT
ComPorts: MSComm
ComPotVal: MSComm
ComBps: String
ComParity: String
ComDataBit: String
CombStopBit: String
PortSettings (Port, PortVal, Bps, Parity, Databit, Stopbit)
ClosePort (Port)
SendMsg (Port, Mesag)
ClearBox (Box)
Send Data
0..*
Get Data
Send Decoded
Data
0..*
0..1
Send Decoded
Data
0..1
0..*
Send Data
Fig. 6: Class Diagram
Data
Data

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 27
3.3.3.4 The Sequence Diagram
The Sequence diagram shows how messages flow from one object to another. It shows the sequence in which activities or
behaviors occur. See Fig 7.
3.3.3.5 The Package Diagram
Package diagram as shown in Fig 8 gives a high-level overview of the system and notes the high-level dependencies (Broch,
Rambaugh and Jacob, 1991). The package diagram below shows how the classes are logically divided into modules. The
dashed arrows show the package dependencies.
Phonebook
User
Register(m,k)
RegNo(n)
Login(m,n)
Access( )
Acquire( )
Acquire( )
Store( )
Registration
Database
Login User Space Text Message Srvice Ceter
Store( )
SendSMS(n)
Flash(n)
Fig. 7: The Sequence Diagram

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 28
3.3.3.6 The Collaboration Diagram
The collaboration Diagram as shown in fig. 9 uses objects and sequence information to show how the objects are connected
statically.
3.3.3.7 The Component Model
The component model shows the dependencies between parts of the code. It is primarily of interest to designers and
maintainers of the system, and forms part of the development view. See Fig 10.
Text Message
Backup
Phonebook
Backup
User
External
System
<<access>>
<<access>>
<<access>>
Fig 8: Package Diagram for the System
USER
LOGIN
USER SPACE
TEXT MESSAGES
PHONEBOOK
3:Login()
4:Access()
REGISTRATION
1:Register
2:RegNo
5:Acquire( )
5:Acquire( )
DATABASE
6:Store( )
6:Store( )
SERVICE
CENTER
7:SendSMS( )
7:Flash( )
Fig. 9: Collaboration Diagram
User
Port
Phonebook
Text
Flash
Send SMS
Fig. 10: Component
Models

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 29
3.3.3.8 The Activity Diagram
The activity diagrams below display all activities that can occur in the system as the values of an object change (Oestereich,
1999). See Fig 11.
3.3.3.9 The Deployment Diagram
The deployment model shows the structure of the runtime system: which parts run on which processors and how the
hardware is configured to provide necessary resources. It contributes to both the physical view and the process view (Fowler
and Scott, 2000). The deployment diagram shows:
 The physical communication links between hardware items (machines and other resources)
 The relationship between physical machine and processes that run on them
The physical system consists of nodes with association between them. A node may be a processor or some other devices
which provide services such as the mobile phone in this case. See Fig 12.
Connect Phone
Fig 11: Activity Diagram for the System
No
Yes
User Space
Login
Register
Disconnect
Backup Text msg
Backup Phonebook
Flash
Send SMS
Send data to Phone
No
Yes
Fig 12: Deployment Diagram
S: MPBT
P1: COM1
M: Phone Memory
M: Comp. Memory
P1: Phone Port
<<Backup Phone Data>>
<<Data Cable>>
<<Return Backup Data>>
1…*
1
Mobile Phone: Siemens
Computer: IBM

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 30
3.3.4 Database Design of the System
Here, we discuss the design of the database used for the storing of acquired data for the system.
3.3.4.1 Entity Relation Model
The entity relation model which shows the relationship between entities and the relationships between then is as shown in Fig
13.
3.3.4.2 Relational Model
The relational model is a tabular representation of the entity relation model. It shows the graphical exact of the database
interface when it is ready for data input. Table 1, 2, and 3.
Table 1: Relational Model - Person
RegistrationNo PersonName Password
Table 2: Relational Model – Phonebook
IdentificationNo PhoneNo ContactName RegistrationNo
Table 3: Relational Model – Text Message
MessageNo Message Sender RegistrationNo
3.3.4.3 Relational Translation
The relational translation for the system is as shown below.
Person (RegistrationNo, PersonName, Password)
Phonebook (IdentificationNo, PhoneNo, ContactName, RegistrationNo)
Text_Message (MessageNo, Message, Sender, RegistrationNo)
PERSON
RegistrationNo
PersonName
Password
TEXT_MESSAGE
MessageNo
Message
Sender
(1, 1)
OWNS
(1, 1)
(1, n)
(1, m)
HAS
PHONEBOOK
IdentificationNo
PhoneNo
ContactName
[1, n] [1, m]
Fig 13: Entity Relation Model

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 31
3.3.4.4 Graph of Relation
The Graph of Relation shows the relationship between different entities. Arrow-head lines are used to show how attributes of
one entity are linked with attributes of some other entity (David, 2004). See Fig. 14.
2.3.4.5 Dictionary of Attributes
The Dictionary of attribute is a form of documentation that shows all attribute, their data types, the entity to which they
belong and a description (David, 2004). See Table 4.
Table 4: The dictionary of Attributes for the system
S/N Attribute Name Data Type (Domain) Entity Description
1 RegistrationNo Number Person Identifies each subscriber
2 PersonName Text(20) Person Subscriber name
3 Password Text(20) Person Subscriber password
4 MessageNo Number Text_Message Identifies each text message
5 Message Text(160) Text_Message The message
6 Sender Number Text_Message The number that sent the message
7 IdentificationNo Number Phonebook Identifies each phone book entry
8 PhoneNo Number Phonebook The contact phone numbers
9 ContactName Text(20) Phonebook The contact names
3.4 Input of the System
The system input would be from the memory of the SIM or mobile phone connected to the computer, or straight from the
keyboard through the graphical user interface of the system resident on the computer. The mobile phone can be connected to
the system at any stage of operation. Once the phone is connected, the commands issued out by pressing buttons on the
graphical user interface are immediately executed. If no phone is connected, commands related to the mobile phone will be
ignored.
Fig 14: Graph of Relation
PERSON
RegistrationNo
PersonName
Password
PHONEBOOK
IdentificationNo
PhoneNo
ContactName
RegistrationNo
TEXT _MESSAGE
MessageNo
Message
Sender
RegistrationNo

1st Annual State Convention of the Nigeria Computer Society 26th May, 2011
NCS, Kogi State Chapter
Theme: ICT - A Catalyst for Change and Development 32
3.5 Output of the System
The output of the system is the phonebook backup and text message backup that are retrieved from the mobile phone, and
stored on the computer memory. Copies of these backup can latter be transferred to the mobile phone when the need arises.
Also as output is the text messages that are and sent from the system through the short message service offered by the
network operator that supplied the SIM. Finally is the “flashing” (make and break calls) capability which is also through the
network operator that supplied the SIM.
4. Summary and Conclusion
4.1 Summary of the Project
This application has been carefully designed. It is highly scalable and robust. Using the system, mobile phone users can
easily and very efficiently store and retrieve the contacts and text messages on their mobile phones. At their convenienc,
users can easily type text messages using the keyboard which is much faster and convenient. They can also decide to send
SMS and/or simply save the message to the phone. With this system as well, ‘Flashing’ has been made more accurate. This
work has been strategically laid out and organized to facilitate understanding of basic concepts involved. Different design
models such as the context diagram, dataflow diagram, and the UML design which consists of several different parts were
considered. The database design was also depicted.
4.2 Conclusion
This system has undergone a series of unit testing, integration testing, and installation testing. It has been found to perform up
to expectation on virtually all grounds. All functions, subroutines, modules, classes and objects are fully functional and
produce the expected results - behaving as expected. This system has actually been implemented and it runs perfectly well.
The system was designed in such a way as to allow for easy expansion or upgrade. Once new classes are built, allowances
have been created within the application where they can easily be plugged and made functional.
References
Bennett, S., McRobb, S. & Farmer, R., (1999), Object Oriented systems analysis and design using UML, McGraw-Hill.
Broch, G., Rambaugh, J. & Jacobs, I., (1991), The Unified Modeling Language (UML): User Guide, Addison-Wesley.
David, A., (2004), Data Modeling and Relational Model. Summer School at the Department of Computer Science, University
of Ibadan.
David, C., (1991), The pan-European cellular mobile radio system. In R.C.V. Macario, Personal and Mobile Radio Systems.
Peter Peregrinus, London.
Feldmann, M. and Rissen J.P., (1993b) GSM Network Systems and Overall System Integration. Electrical Communication.
Fowler, M. & Scott, K., (2000), UML Distilled, Addison Wesley.
Maduka I., (2005), Development of a Phonebook Software, Thesis submitted to the Department of Computer Science,
University of Ibadan.
McKelvy, M., (1996), MCSD: Visual Basic 6 Desktop Application Study Guide. Gira Sound.
Oestereich, B., (1999), Developing Software with UML, Addison Wesley.
Pfleeger, S. L., (2001), Software Engineering Theory and Practice.
Stevens, P. & Pooley, R., (1999), Using UML Software Engineering with Objects and Components. Addisson-Wesley.