steps: insert/swipe debit card check if card is of same bank or other(it won't impact the flow from enduser perspective,still to be verified) enter pin(validations on pin) select lang.(validation on lang.) select transaction type(validation on transaction type)-withdrawal/fast cash option choose account(savings/current) enter amount(validation on withdrawal amount & account balance,amount available in ATM) daily transaction limit validation,etc validation on currency notes when amount criteria fulfilled print receipt-yes/no validation validate printed receipt print balance on screen validation after transaction completes,automatically logged out error messages should be displayed on appropriate events(and the application shouldn't crush or machine shouldn't hang on invalid transaction) validating the application when user cancels transactionin between processing withdrawal,etc