An online shop sells pet food and accessories. Customers can choose goods and conclude their orders on its website. The order is processed according to these rules:

A customer enters his or her order and clicks SUBMIT. Depending on its total value, the order is set to either of the following states:
- APPROVED, if the value is less than or equal to $100.
- PENDING, if the value is greater than $100 and the shop's personnel have to verify the validity of the online payment.
For PENDING orders, shop personnel can click one of the following:
- APPROVE if the payment is confirmed, thereby setting the order to the state of APPROVED.
- CANCEL if the payment is invalid, thereby setting the order to the state of CANCELED.
For orders in an APPROVED state, the shop personnel choose the SHIP action after the goods are actually sent, thereby setting the order to a state of SHIPPED.

Prepare the optimal (effective and efficient) set of test cases, each containing either a complete or partial state lifecycle, required to test this system.