Creating structural business rules at the outset will help guide the design throughout the rest of the sections. An example of this type of business rule not related to Amazon is A car may be driven by many drivers; each driver drives one or more cars. Each business rule should describe the entities involved, the relationship between the entities, and the optionality and plurality constraints for each entity. Try to make sure that you have created all the structural business rules required for each use case.

Use Case 5 - Product Shipment by Amazon

This occurs when Amazon ships the product that consumer has purchased:

1. Amazon packages he purchased products and assigns an identifier to package so that it can be tracked.
2. Amazon links the package to the customers order.
3. Amazon ships the package to the default address linked to the customers account.
4. Amazon notifies the customer that it has been shipped and provides the customer with the tracking ID.