Background: The database is down, so orders received from the shop cannot be processed immediately
Source: User
Stimulus: Sends an order to the shop
Reaction: The system detects the database is down and queues the order for 1 day. As soon as the database is back up, the queued orders are processed
Metric: If the database downtime is less than 1 day, the number of orders received must be equals to the number of orders queued.