UML in 10 mins

"An automated teller machine or automatic teller machine" (ATM) (American, Australian, Singaporean, Indian, and Hiberno-English), also known as an automated banking machine (ABM) (Canadian English), cash machine, cashpoint, cashline or hole in the wall (British, South African, and Sri Lankan English), is an electronic telecommunications device that enables the clients of a financial institution to perform financial transactions without the need for a cashier, human clerk or bank teller.
On most modern ATMs, the customer is identified by inserting a plastic ATM card with a magnetic stripe or a plastic smart card with a chip that contains a unique card number and some security information such as an expiration date or CVVC (CVV). Authentication is provided by the customer entering a personal identification number (PIN). The newest ATM at Royal Bank of Scotland allows customers to withdraw cash up to £100 without a card by inputting a six-digit code requested through their smartphones.
Using an ATM, customers can access their bank accounts in order to make cash withdrawals, get debit card cash advances, and check their account balances as well as purchase pre-paid mobile phone credit. If the currency being withdrawn from the ATM is different from that which the bank account is denominated in (e.g.: Withdrawing Japanese yen from a bank account containing US dollars), the money will be converted at an official wholesale exchange rate. Thus, ATMs often provide one of the best possible official exchange rates for foreign travellers, and are also widely used for this purpose." [Automated teller machine. Wikipedia]
The UML activity diagram example "Cash withdrawal from ATM" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

"Credits and deposits.
To add credit to an account by bringing cash to a bank in person, the account holder can fill a small credit slip or deposit slip. The total amount of each note and coin is counted and entered on the slip, along with who it is paid in by and the date. The cash and details are counted and checked by the teller at the bank, if everything is in order the deposit is credited to the account, the credit slip is then kept by the bank and the credit slip booklet is stamped with the date and then returned to the account holder.An account holder uses their passbook to record their history of transactions with their bank." [Passbook. Wikipedia]
The UML activity diagram example "Deposit slip processing" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

This example of UML class diagram models bank account system.
"A bank account is a financial account between a bank customer and a financial institution. A bank account can be a deposit account, a credit card, or any other type of account offered by a financial institution. The financial transactions which have occurred within a given period of time on a bank account are reported to the customer on a bank statement and the balance of the account at any point in time is the financial position of the customer with the institution. a fund that a customer has entrusted to a bank and from which the customer can make withdrawals." [Bank account. Wikipedia]
This bank account system UML class diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the ATM UML Diagrams solution from the Software Development area of ConceptDraw Solution Park.