The most recent implementation of rules was in the pharmaceutical distribution environment where they had to create rules to determine what to ship to which farmacies (CVS, Revco, Walgreen), determine conversion factors between different companies shipping (cases versus boxes versus pack, etc) and determine if a specific costumer get a brand name versus a generic name.
Another one was on airline catering rules which let you determine what to load on which flights based of the location of the flight, duration, number of seats sold, etc. Like load ice in Atlanta but don't load in Miami if the flight is not an international flight unless the flight has been overbooked.
Also insurance is a big market for business rules, like determining fraud on a claim, etc. For example if both drivers have had accident before in the same set of cities (red flag) type of rules.
