Here are some examples of business rules for Rental Cars-R-Us that use the vocabulary defined and terms defined in other similar concept diagrams.
• Each rentalalways hasexactly one requested car group.
• The duration ofa rentalmust not be more than 90 days.
• A driver ofa rentalmust bea qualified driver.
• A rentalmust incura location penalty chargeif the drop-off location ofthe
rental isnot the return branch ofthe rental.
• The rental charge ofa rental isalways calculated inthe business currency ofthe
rental.
• A rentalmay be openonly if an estimated rental charge is provisionally charged to
the credit cardof the renter ofthe rental.
• The fuel level ofthe rented car ofa rentalmust be full atthe actual start date/
time ofthe rental.