Business Rules: Key Principles and Best Practices
1. Requirements as the Principal Elements
The requirements are the principal elements. Rules are essential to business models and technology models, and each specifies the same thing.
2. Independent of the Process
Rules are behavioral constraints that support business activities. They are not processes or procedures and should not be contained within them. Rules are applied throughout processes and procedures to ensure consistency across all business activities.
3. Provide Knowledge, Not a Byproduct
Rules build on facts, and facts, as concepts, are expressed through terms. Business concepts and facts make assertions about these concepts; rules constrain and support facts. Rules must be explicit. You should not assume any rule about any concept or fact. Rules are principles that define what the business knows about itself—they are fundamental business knowledge. Rules need to be nurtured, protected, and managed.
4. Designated Non-Procedure
Rules should be expressed as declarative sentences in natural language. If something cannot be expressed clearly, then there is no rule. A series of statements does not contain an implicit sequence. Rules should be defined regardless of who is responsible for compliance and where and how they are enforced.
5. Business Service, Not Technology
Rules are about management practices and business governance, motivated by goals and objectives, and shaped by internal and external factors. There is always a cost associated with applying rules. The cost of applying rules must be assessed and balanced, taking into account the risks and opportunities. Having many rules does not guarantee their application; it is often better to have a limited number of well-defined rules. An effective system can be based on a small number of rules, becoming more discriminatory as the system improves and becomes more intelligent.
6. Managing Business Logic, Not HW and SW Platforms
Business rules are vital, long-term business assets. The business rules are more important for the business than HW and SW platforms. Business rules should be organized and safeguarded so they can be used with new HW and SW platforms. Rules and the ability to change them effectively are key factors for improving a company’s adaptability.
7. Processes Guided by Rules
Rules define the boundary of acceptable business activity. Rules often require special handling or specify violations. Any act resulting from violating a rule is an act like any other. To ensure maximum consistency and reuse, treating unacceptable acts should be separated from managing acceptable acts.
8. Rules-Based Architecture
A system based on business rules is intentionally established to allow the continuous change of business rules. The platform on which the system runs should support this evolution. The way a rule is specified determines whether it remains hidden from those who use it. The relationship between events and rules is generally many-to-many.