Consider a retail bank which collects money from customers and in return gives them an interest at pre determined rate. Our objective is to automate this process of interest calculation. The system developed should calculate interest daily for each account having balance more than zero at the correct interest rate. This interest calculated will be cumulatively stored in a table which will be updated every day. Remember that the balance on which interest is calculate daily will change because the customer may deposit or withdraw money. Every month the cumulative interest calculated will be credited to the customer. After this point in time the cumulative interest stored should be set to zero because the customer has benefited for the period specified. Before interest is credited to the customer’s account tax should be debited from the interest according to prevalent government laws.