The Data Model Resource Book, Volume 3: Universal Patterns for Data Modeling

Silverston c08.tex V2 - 11/21/2008 3:12am Page 442

442 Chapter 8 ■ Business Rules: How Things Should Work

The rule specifies that if all of these conditions are met, a PRICE

COMPONENT RULE discount percentage (an outcome) of ‘‘25’’ is applied.

You could have a great number of rule instances that are maintained in

PRODUCT COMPONENT RULE because there may be amounts or percent-

ages for any combination of factors that influence prices. For example, there

could be a price (price amount) for product ‘‘A245,’’ indicating you charge

$9.99 (US Dollars) for this product in New York State, $10.99 (US Dollars) in

California, £9.99 in the UK, and HK$99.99 in Hong Kong. You could adjust

these prices by applying any specific or generalized factors. So you could

say that the price is $8.99 in New York State for a ‘‘Partner’’ (ROLE TYPE)

when the ORDER VALUE is over ‘‘$1,000 (US Dollars).’’ There may be a

PRICE COMPONENT RULE that has a PRICE COMPONENT RULE TYPE

of ‘‘Surcharge’’ and is for an amount of ‘‘$100.00’’ for any delivery location

outside of the 500 mile delivery from distribution center limit (see point 6 of

the rule statement example).

NOTE

Notice that in this example, not all instances of PRICE COMPONENT RULE

relate to a PRODUCT or PRODUCT FEATURE. For example, Pricing rule 124 does not

relate to a particular PRODUCT or PRODUCT FEATURE. There could be other

discounts that apply just to a particular PRODUCT ...