Example

An air cargo company has a manual process for generating flight plans. These flight plans assign cargo shipments to a specific aircraft. Each flight plan is assigned a flight number. The cargo company owns a small fleet of three planes: two Boeing 747s and one McDonnell-Douglas DC-10 freighter. Each airplane type has a maximum cargo weight and volume that cannot be exceeded. Each airplane type also has a tail number that identifies it. A cargo shipment has characteristics like weight, volume and a manifest number.

Assume that the company wants to build a system that automatically checks flight plans to ensure that no scheduling rules or guidelines are violated. One of the many business rules that needs to be checked by this system is: