ATM Case Study1

8/8/2019 ATM Case Study1

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Case Study A Bank wishes to introduce ATM service to providelimited facilities to her customers. Customers may get

ATM cards on request. Users may view their balance or transfer or withdraw money using these cards. Cardsmay be used to access many accounts and an accountmay be accessed using different cards. A card may beblocked temporarily or permanently (e.g. If it is lost) bythe Bank. A PIN is associated with each card to verifythe authority of the user. There is an OD limit associatedwith each cheque account. Theoretically, any amountmay be withdrawn from a cheque account at any time(provided it is less than the balance+Odlimit). There isno OD facility for a savings account.


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Case Study (cty)

The personal information of the customers andtheir account details are already maintained bythe Banks main system. A subsystem is

required to handle the ATMs functionality. Twohardware systems Card reader and Moneydispenser will communicate with this subsystem.The card reader reads the Cards ID and passesit to the system. It is also able to eject the cardwhen an eject signal is received from thesystem. Similarly the money dispenser is able todispense the required amount of money.


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Case Study-3The Limited ATM system is required to provideat least the following operations.

Enter a new card / new account detail

Block /Reactivate/Cancel a cardView the balance of the accountWithdraw money from the accountTransfer money from one account to another

Change the PIN of a cardThe validity of the card and the authority of theUser will be checked for each transaction session.


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Apply for Card

Assign Pin

Finalise Card

Manager

Record Detail

Approve

Receive Card

ClerkClient

:Card[Recorded]

:Card[Approved]

:Card[Finalised]

:Card[active] Applying for

New Card

A Business Activity

Diagram


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A Business

ActivityDiagramInsert Card

View Balance

Select Service

Client arrives at ATM

Give PIN

[CARD valid]

[PIN OK]

[Quit]

Eject Card

[CARD valid]

[PIN OK]

Withdraw

[withdraw]

Client

TransactionClient leaves ATM


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Glossary

ATM Card -Withdraw -


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Requirement List

Client shall view the balanceClient shall withdraw money within a limitClient shall change the PIN

Bank Clerk shall store a new CARD detailBank Clerk shall add another account to aCARD

Shall check the CARDs validityShall verify the PINShall use 3-DCS (168 bits) encoding


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Grouping the Candidate Requirements

CARD MANIPULATION Clerk store a new CARD detail Clerk add another account to a CARD

Clerk & Client shall fix new PIN first time Client shall change the PIN

TRANSACTIONS Client shall view the balance (within 2 minutes) Client shall withdraw money from savings/

current account within the limit Client shall transfer money within the limit


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Client

transfer

withdraw

view Balance

Use Cases TransactionsTransactions

Add structures


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Client

transfer

withdraw

view Balance

Use Cases TransactionsTransactions

print Balance

get Accounts

S tructures added


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Clerk

add new account

add new card

fix PIN

Use Cases Card ManipulationCard Manipulation

Client

Add structures


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Clerk

add new account

add new card

fix PIN

Use Cases Card ManipulationCard Manipulation

Client


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ATM- Withdraw From CurrentName : Withdraw From Current

Actor : ClientPre-conditions : User already logged-in

A menu is active with withdraw optionPost-conditions : Amount is deducted from users accountPurpose : To allow the client to withdraw moneyDescription:

(1) Client initiates this usecase by selecting withdraw(2) System get all the accounts (use case get Account)(3) System displays all the accounts and prompts to select any one(3) Client selects one account(4) System prompts for the amount(5) Client indicate an amount(6) System issues money, update record, and confirms

Alternative courses:(3) & (4) System selects the only one available account(6) requested amount is bigger than balance, system display message

Errors:

Issue Cash?


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Usecase Description-

Withdraw from Savings


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Prototype

Withdraw from CurrentSelect A ServiceWithdrawView BalanceTransfer

Select An AccountChequeSavings (House)Credit

Give An Amount

OK

Suceess

Take Your Money Another Transaction?Get Your Card? OK

OK


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ATM-Withdraw System gets

all accounts

Client selectsFast cash

Client Select One Account

Client selecetd withdraw

Displays allaccounts

[accounts>1]

Eject Card

[account=1]

System asks for Amount to withdraw

[amount > balance]Client types

amount

Issue cash

Display message

[amount > balance]

[Quit]


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Complete other Usecases!

View BalanceTransfer

Add CardAdd AccountChange PIN

Change StatusCheck PIN


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ATM ; E-R Diagram Classes (ITE-1)

ATMCustomer ATMCheque ATMSavings

ATMCard

custID

getCustID()accIDbalanceoDlimit

cardNopinstatus

getAccID()setBalance()getBalance()

getAccID()setBalance()getBalance()

accIDbalance

getCardID()setPIN()checkPIN()setStatus()getStatus()

1..*1..*

0..* 0..*

1..*

1

0..*0..*

1..* 1..*

For the time being there isno need for an AssociationClass or Attributed

Association

What if, the date joined (an Account to a Card) attributeis important ?


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Realize Usecases

Identify Systems TasksIdentify Collaborating ObjectsAllocate ResponsibilitiesDraw CRCDraw ColloborationAssign a Ctrl class (and a UI class- if necessary)for each usecase.Draw Collobaration againUpdate Class diagram


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Withdraw From CurrentName : Withdraw From Current

Actor : ClientPre-conditions : User already logged-in

A menu is active with withdraw optionPost-conditions : Amount is deducted from users accountPurpose : To allow the client to withdraw moneyDescription:

(1) Client initiates this usecase by selecting withdraw(2) Sy stem get all the accounts (use case get Account)(3) Sy stem displays all the accounts and prompts to select any one(3) Client selects one account(4) Sy stem prompts for the amount(5) Client indicate an amount

(6) Sy stem issues money, update record, and confirms Alternative courses:

(3) & (4) System selects the only one available account(6) requested amount is bigger than balance, system display message

Errors:

Identify System s Tasks

Identify Nouns


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System s Tasks Identified

(1) System gets all the accounts on Card(2) System displays the details of Accounts

(3) Prompts to select one(4 System prompts for the amount(5) System issue money

(6) Update records (update what?)H ow to allocate these tasks to different classes?


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2

Use case Realization!

withdraw

Client

:Account :Card

withdraw1

Identify Collaborations


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Collaboration Diagram (Initial Idea)!

Client ::Card

::Account

getAllAccDetail() *getAccDetail()21

withdraw(acc,amm)3withdraw(amm)4


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withdraw(am)

::withdrawUI ::withdrawCtrlClient

::Card::Cheque

2

1

35.1

getAllAccDetail()

start U I()selectAccount

withdraw(cID)

*getAccDetail()1.1

4 proAmount withdraw(acc,am)5

0

Collaboration Diagram,

with U I and CTRL objects!

Issue Cash?


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ATMCustomer ATMCheque ATMSavings

ATMCard

custID

getCustID()accIDbalanceoDlimit accName

cardNopinstatus

getAccID()setBalance()getBalance()getAccDetail()withdraw(amo)


accIDbalanceaccName

getCardID()setPIN()getPIN()setStatus()getStatus()getAllAccDetail()

1..*1..*

0..*0..*

1..*

10..*0..*

1..* 1..*

Analysis Level Class Diagram : Ite-2

ATMwdU I

s tartUI();s electAcc();proAmount();

ATMwdCTRL

withdraw(cID)withdraw(aID,amo)

What next? Identify Super-Sub & Aggregations


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Analysis Level Class Diagram (Ite-3) ATMCustomer

ATMSavings

ATMCard

custIDgetCustID()

cardNopinstatus

ATMCheque

oDlimit

withdraw(amo)

withdraw(amo)


0..*

1..*

1..*

1

1..*

ATMwdCTRL


ATMwdU I


ATMAccount


accIDbalanceaccName

1..*


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Analysis Level Class Diagram (ver-2) ATMCustomer

ATMSavings

ATMCard

custIDgetCustID()

cardNopinstatus

ATMCheque

oDlimit

withdraw(amo)

withdraw(amo)


1..*

1

1..*

ATMwdCTRL


ATMwdU I


ATMAccount


accIDbalanceaccName

1..*

ATMCustAcc

Which version is better, why?


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Sequence diagram

:Card :Account

getAllAccDetail()

withdraw(acc,am)

*getAccDetail( )

Client

withdraw(am)

with entity objects only

Use Case: withdraw


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With Boundary & Control Classes

*getAccDetail():withdrawUI

:withdrawCtrl :Card :Account

withdraw()proAmount()

withdraw()

startUI() *getAllAccDetails()

Client

Use Case: withdraw

selectAccount()

Sequence diagram

Issue Cash?


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State Transitions

Include relevant State Transition Diagrams(or Activity Diagrams)


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StatechartPe nding

OnUs e

Laps e d

fixP IN()

afte r [1 y e ar]

Card()

CARD

Active

B lock e d

s e tStatus()

OnUse

~Card()


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Withdraw- Operation SpecificationPre- and Post-condition Pair

pre-conditions:CARD is validACCOUNT is valid

ACCOUNT is associated with CARDamount is valid

post-conditions:if amount is greater than ACCOUNT.b alance

value of ACCOUNT.b alance set equal toACCOUNT.b alance-amount

value of result set equal to success

otherwisevalue of result set equal to failure

Issue Cash?


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Structured English- withdrawget all the accounts associated with CARDif there are more than one ACCOUNT

Do while there is no more ACCOUNTS leftget all the details associated with ACCOUNTdisplay details

endDo

set ACCOUNT to user selected ACCOUNTelse

set ACCOUNT to the only existing ACCOUNTendIfif ACCOUNT.balance is greater than amount

set ACCOUNT.balance to ACCOUNT.balance amount

set result to TRUE

elseset result to FALSE

endIfreturn result

Issue Cash?


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Get AccountDetails

[NoOfAccounts = 1]

[amount < =A . balance]

A.balance A.balance-amount

Result TRUE

List an Accountdetails

AOnly Account

Activity Diagram- Withdraw

[NoOfAccounts > 1]

Get amount Get UsersChoice (say A)

[more]

[no more]

[amount >A . balance]

Result FALSE

Issue Cash?

Documents

ATM Case Study1