System Behavior (Use Cases)
Use Case Diagram

Primary Actors:
- Customers
- Employees
- Managers
Use Cases:
- Place Order
- Cancel Order
- View Order Details
- View Order History
- Ship Order
- View Sales Report
Secondary Actors:
Use Case Narrative: Place Order
Use Case Name
Place Order
Primary Actor
Customer
Goal
The customer successfully places an order for a product.
Preconditions
- The customer is registered and logged into the system.
- The products to be ordered exist in SAP.
Main Success Scenario
- The customer enters a product SKU.
- The customer enters the desired quantity.
- The customer submits the order.
- The system validates the desired quantity.
- The system validates that the product exists SAP.
- The system creates the order.
- The system provides an order confirmation to the customer.
Extensions (Alternative Flows)
- 4a. Non-positive quantity:
- The system notifies the customer and suggests entering a valid quantity.
- 5a. SAP is unavailable:
- The system notifies the customer that product information cannot be retrieved at this time.
- 5b. Product not available:
- The system notifies the customer and suggests removing or replacing unavailable items.
Postconditions
- The order is created and stored in the system.
- The customer receives an order confirmation.
Use Case Narrative: Cancel Order
In a Real Life Project, we would write Use Case Narratives for the other Use Cases too. In this Sandbox Project, I’ve omitted writing the other Use Cases.