TTY Ltd sells ingredients to restaurants. Customers may only make orders by telephone calls but may order multiple times on a single day. An order can include multiple items. The salespeople create a sales order when an order received. The customer’s name and a list of inventory items that the customer wants to purchase are shown on the sales order.

TTY arranges delivery periodically on Mondays and Fridays. It occasionally runs out of some items, in which case another delivery will be arranged. TTY allows customers to pay by instalment within 15 days. Some customers may settle all sales orders by a single payment.

TTY deposits all the money received into its main savings account.

1. Using the above information, draw an REA diagram with cardinalities for TTY Ltd’s revenue cycle.

 

2. Using your REA diagram, develop a relational database in 3rd Normal Form (3NF) for TTY Ltd. You should clearly identify the table name, primary key, foreign key and one non-key attribute for every table in your database design.