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

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What Is a Business Rule? 415

rules might use the Level 2 Business Rules Pattern, whereas an enterprise

wanting a single, generalized structure for all business rule models might use

the Level 3 Business Rules Pattern.

In this chapter we illustrate this pattern with the following two business

rules scenarios:

The rules regarding how to respond, under different conditions, to cer-

tain EVENT TYPE(s) (an event is an activity that happens at a given place

and time and that may trigger other activities, for example, a phone call

responding to a complaint from a customer).

The rules, based upon various factors, regarding pricing for a PRODUCT

or PRODUCT FEATURE.

Although we focus on these two scenarios, please note that the patterns in

this chapter work for all different types of business rules.

This chapter includes the following:

The definition of business rules

The different patterns that support business rule definition

The relevance of each pattern

Insights into each pattern

When to use and not to use different patterns

A synopsis of each pattern’s pros and cons.

What Is a Business Rule?

Business rules may be defined in many different ways. For example, they can

be defined broadly such as ‘‘a directive intended to influence or guide business

behavior’’

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or narrowly such as ‘‘a business data rule is a constraint on the

data beyond the constraints implied by