How to write top 50 test case for ATM ?

Positive Test cases

  1. Verify that the system gets initiated when user turns on the switch. 
  2. Verify that the slot for inserting the ATM Card is as per the specification
  3. Verify that when user inserts the ATM card into the slot properly, appropriate options get displayed on the screen.
  4. Verify that the touch screen of the ATM machine is smooth and operational.
  5. Verify that user is presented with option to choose language for further operations.
  6. Verify that the system accepts and reads the ATM card.
  7. Verify that an option to continue and enter credentials is displayed to user when user inserts the card correctly.
  8. Verify that the system doesn't display any  card/bank account details before the user enters correct pin number.
  9. Verify that there are limited number of attempts up to which user is allowed to enter PIN.
  10. Verify that the system accepts customer's PIN, if they enter the correct one.
  11. Verify that system accepts initial cash amount, when user selects it on the screen.
  12. Verify that the system is able to setup a connection to the bank securily. 
  13. Verify that the system shows appropriate options to the customer so that they can select an account to withdraw from.
  14. Verify that the system allows the customer to carry on the transaction appropriately.
  15. Verify that the system allows the user to carry multiple transactions in one session.
  16. Verify that the font of the text displayed on the ATM screen is as suggested in the Requirement Specifications document.
  17. Verify that the system performs a legitimate withdrawal transaction.
  18. Verify that the system doesn't allow the user is not allowed to carry on with any operations further and ATM gets  like blocked by the ATM machine, if user enters incorrect PIN each time and total number of attempts to enter PIN correctly are exhausted.
  19. Verify that the pin is encrypted and when the user types it on the system.
  20. Verify that the user is presented with different account type options like- saving, current etc.
  21. Verify that user is able to fetch the account details appropriately ex. available balance.
  22. Verify that user same amount of money gets dispatched as entered by user for cash withdrawal
  23. System verifies that it has sufficient cash on hand to fulfill the request
  24. Verify that user is only allowed to enter amount in multiples of denominations as per the specifications
  25. System verifies that customer's balance is sufficient to fulfill the request
  26. Verify that user is prompted to enter the amount again in case amount entered is not as per the specification and proper message should be displayed for the same
  27. A withdrawal transaction can be cancelled by the customer any time prior to choosing the amount
  28. Verify that user cannot fetch more amount than the total available balance
  29. Verify that user is provided the option to print the transaction/enquiry
  30. Verify that user user's session timeout is maintained and is as per the specifications
  31. Verify that user is not allowed to exceed one transaction limit amount
  32. Verify that user is not allowed to exceed one day transaction limit amount
  33. Verify that user is allowed to do only one transaction per pin request
  34. Verify that user is not allowed to proceed with expired ATM card
  35. Verify that in case ATM machine runs out of money, proper message is displayed to user
  36. Verify that in case sudden electricity loss in between the operation, the transaction is marked as null and amount is not withdrawn from user's account
  37. Session ends when customer chooses not to do another transaction
  38. System is shut down when the switch is turned "off" . Connection to the Bank is terminated when the system is shut down
  39. Machine accepts both Visa and Mastercard credit and debit card
  40. Machine prints out balance inquiry standalone as part of menu operation.
Negative Test cases
  1. System rejects an unreadable card
  2. System handles an invalid PIN properly. 
  3. Customer is asked to reenter PIN
  4. Correct re-entry of PIN is accepted
  5. A correctly re-entered PIN is used for subsequent transactions
  6. Incorrect re-entry of PIN is not accepted
  7. Correct re-entry of PIN on the second try is accepted
  8. Correct re-entry of PIN on the third try is accepted
  9. Three incorrect re-entries of PIN result in retaining card and aborting transaction
  10. Machine generates invalid money error due to money asked larger than the savings account balance