Use Case Diagram for the ATM System

Let’s build the ATM system’s use case diagram and understand the relationship between its main actors and functions. First, we’ll define the different elements of our system, followed by the complete use case diagram.

System

Our system is the ATM system. It manages secure, card-based access for bank customers to perform key banking transactions remotely.

Actors

Let’s define the main actors of our ATM system.

Primary actors

• Cardholder: The user who interacts with the ATM to perform banking transactions such as inserting/removing the card, entering PIN, and carrying out account operations.

Use cases

In this section, we will define the ATM’s use cases. We have listed them according to their interactions with a particular actor.

Cardholder

• Insert card: Insert the ATM card into the machine.

• Enter PIN: Enter their PIN to verify identity.

• Change PIN: Change the card’s PIN.

• Select transaction: Initiate a transaction (generalization of the next four):

  • Balance inquiry: Check account balance.

  • Funds transfer: Transfer money between accounts.

  • Cash withdrawal: Withdraw cash.

• Enter amount: The cardholder enters the amount they want to transfer or withdraw.

• Cancel transaction: Cancel a transaction.

ATM System

• Verify cardholder identity: Validate the card and the cardholder’s credentials.

• Check withdrawal limits: Validate the ATM’s transaction limits and the cardholder’s bank limits.

• Check account transaction limits: Validate that the transaction is within the account’s permissible limits.

• Return card: Eject the card after the transaction or cancellation.

• Dispense money: Dispense cash during withdrawal.

• Dispense receipt: Print and provide a receipt for the transaction.

Relationships

This section describes the relationships between and among actors and their use cases.

Associations

The table below shows the association relationship between actors and their use cases.