Consider the sequence of actions performed by typical Internet users:
- New users arriving at an eCommerce site for the first time may create accounts. Existing users may authenticate themselves by providing their unique identifiers and passwords.
- After successful authentication, users may add items they are interested in purchasing to their shopping carts and view the list of items in their carts. (Of course, users may also wish to simply browse the electronic store without purchasing items.)
- When viewing shopping cart contents, users may wish to change the quantities of items they have selected.
- Site visitors may then checkout by confirming they would like to purchase the items in their shopping carts. The items in customers' shopping carts are then entered into the database. Users may then continue shopping or logout.
- Customers may also wish to return to the site at a later time to ascertain the shipping and delivery status of items they have purchased.
The flowchart below describes the typical interactions of site visitors with the shopping cart application.