Use case : Browse Catalog
Main sequence:
1 Customer requests to browse catalog .
2 System displays catalog information to customer .
3 Customer selects items from catalog .
4 System displays an itemized list containing each item description and price , as well as the total price .
Alternative sequence: 
Step 3: Customer does not select item and exits .
Use case name: Make Order Request
Main sequence:
1 Customer provides order request and customer account Id to pay for purchase .
2 System retrieves customer account information , including the customer’s credit card details .
3 System checks the customer’s credit card for the purchase amount and , if approved , creates a credit card purchase authorization number .
4 System creates a delivery order containing order details , customer Id , and credit card authorization number .
5 System confirms approval of purchase and displays order informa-tion to customer .
Alternative sequences:
1. Step 2: If customer does not have an account , the system prompts the cus-tomer to provide information in order to create a new account . 
The customer can either enter the account information or cancel the order .
2. Step 3: If authorization of the customer’s credit card is denied , e.g. , invalid credit card or insufficient funds in the customer’s credit card account , the system prompts the customer to enter a different credit card number . 
The customer can either enter a different credit card number or cancel the order .
Use case : process delivery
Main sequence:
1 Supplier requests next delivery order .
2 System retrieves and displays delivery order .
3 Supplier requests inventory check on items for delivery order .
4 System determines that items are available in inventory to satisfy delivery order and reserves items .
5 System displays inventory information to Supplier and confirms that items are reserved .
Alternative sequence: Step 4: If item is out of stock , system displays warning message .
Use case name: confirm shipment and bill custormer
Main sequence:
1 Supplier prepares shipment manually and identifies that delivery order is ready to ship .
2 System retrieves customer account information , including the invoice and customer’s credit card details .
3 System updates inventory to confirm purchase .
4 System charges customer’s credit card for purchase and creates a credit card charge confirmation number .
5 System updates delivery order information with credit card charge confirmation .
6 System sends email confirmation to customer .
7 System displays confirmation to the supplier to complete shipment of the delivery order .