1. 1
Project Name : ATM Software System
A local bank intends to install a new automated teller machine (ATM) to allow
users to perform basic financial transactions .Each user can have only one account
at the bank.ATM users should be able to view their account balance, withdraw
cash and deposits funds.
Account schema hold the record of user like his account id account pin and balance.
Account
account_id : ℕ
account_pin : ℕ
balance : ℕ
balance ≥ 0
i. account _id to identify the user account
ii. account _pin to verify the user
iii. balance is always greater or equal to zero
The amount of ATM is stored in cash dispenser which is filled on daily basis. And the maximum
amount which is stored in cash dispenser is 10000.
CashDespenser
out_money : ℕ
limit : ℕ
limit = 10000
out_money = 10000
i. limit is initialize to 10000.

2. 2
ii. out_money is initialize to 10000.
A Deposit Slot to receive the money from user and add it to his account.
DepositSlot
in _ money : ℕ
envelop _ received : {yes , no}
in _ money > 0
i. in_money to store the amount of entered amount to add in his account.
ii. envelop_recived to check either user gives the amount to deposite slot or not.
iii. in _money must be greater then 0.
ATM consists of account, cash despenser, and a deposit slot. ATM by using database of bank
verify the user.
ATM
Account
CashDespenser
userauthentication({account_id↦account_pin)} : {yes ,no}
DepositSlot
balance = DB_balance(account_id)
i.
balance is initialize with the amount stored in the bank database regarding account id.

3. 3
An operation to refill ATM Cash Despenser
Refill
ΔATM
amount ? : ℕ
reply! : MESSAGE
amount + out_money ≤ limit
out_money ′ = out_money + amount
Pre-Condition : By adding amount in Cash Despencer it will not exceed the limit.
Add the entered amount in the out_money .
An operation for verification of user.
Authentication
Ξ ATM
account ? : ℕ
pin ? : ℕ
reply : MESSAGE
userauhtentication({account?↦pin?}) = yes
reply! = acess granted
Pre-Condition: userauhtentication must be “yes”.
.

4. 4
BadAuthentication
Ξ ATM
account ? : ℕ
pin? : ℕ
reply : MESSAGE
userauhtentication({account?↦pin?}) = no
reply! = invalid user
Pre-Condition : userauhtentication must be “no”.
MESSAGE== acess granted | invalid user
Robust Authentication= Authentication ∨ BadAuthentication
An operation to check the current balance.
BalanceInquirey
Ξ ATM
showbalance ! : ℕ
showbalance ! = balance
SuccessfulBalanceInquire= Authentication ∧ BalanceInquirey
An operation to withdraw the money.

5. 5
WithDraw
Δ ATM
amount ? : ℕ
reply ! : MESSAGE
amount ? ≤ balance
amount ? ≤out _ money
balance ′ = balance – amount
out_money ′ = out_monet - amount
reply ! = transaction_successful
Pre-Condition :
i. Enter amount must be less then equal to balance.
ii. Enter amount must be less then equal to out_money.
Entered amount is subtracted from balance.
Entered amount is subtracted from out_money.
SuccessfulWithDraw= Authentication ∧ WithDraw
To deal the case when user not have enough balance.
BadWithDraw(1)
Ξ ATM
amount ? : ℕ
reply ! : MESSAGE
amount ? > balance
reply ! = Insufficent_Balance
Pre-Condition : Enter amount is grater then balance.

6. 6
To deal the when ATM has not have enough balance.
BadWithDraw(2)
Ξ ATM
amount ? : ℕ
reply ! : MESSAGE
amount ? > out _ money
reply ! = Not_enough_amount_in_ATM
Pre-Condition : Enter amount is grater then out_money .
MESSAGE== transaction_successful |Insufficent_Balance | Not_enough_amount_in_ATM
Robust WithDraw = SuccessfulWithDraw ∨ BadWithDraw(1) ∨ BadWithDraw(2)
An operation to deposit money in Account.

7. 7
Deposite
Δ ATM
amount? : ℕ
env? : envelop _ received
reply! : MESSAGE
env?= yes
amount? > 0
balance ′ = balance + amount
reply! = Transaction_Successful
Pre-Condition : User must give the envelope of money.
Given amount must be grater then 0.
Entered amount added in the balance of user.
SuccessfulDEPOSITE= Authentication ∧ Deposite
To deal with the case when user don’t give the envelope of user.

8. 8
BadDeposite
ΞATM
amount? : ℕ
env? : envelop _ received
reply! : MESSAGE
env?= no
reply! = Plz_Give_Amount
Pre-Condition: User don’t give the envelope of money.
MESSAGE== Transaction_Successful | Plz_Give_Amount
Robust Deposite = SuccessfulDeposite ∨ BadDeposite