Business rules and tables can be used to model and apply regulations, procedures, and various kinds of complex business decisions and calculations.  But they can do so much more:  checking the quality, designing and restructuring, simplifying, impact analysis, translation, etc.

The regulations lifecycle

We are surrounded by rules and regulations.  The purpose of the business rules approach need not be restricted to managing and implementing existing regulations.  Business rules and tables are well applicable throughout the lifecycle of the regulations, from the initial design of new regulations to the maintenance and enforcement of existing ones.

Here are the major steps in dealing with regulations:

• Designing & constructing regulations
• Modeling regulations
• Identifying applicable regulations
• Capturing, acquiring, & representing regulations
• V&V (Validating & verifying regulations ~ harmonisation & quality)
• Communicating and translating regulations
• Implementing regulations
• Testing regulations
• Maintaining regulations
• Improving regulations
• Enforcing regulations

The added value of business rules and tables throughout the lifecycle

Business rules and tables can be used throughout the entire lifecycle of regulations.  Some example application areas are:

Designing regulations

An important asset of business rules is that they are based on clear terms and facts.  Text is much more ambiguous and leaves room for interpretation.  Although such ambiguity and flexibility of interpretation might be a desired outcome, it creates a lot of problems, e.g., when regulations have to be automated.  When designing new regulations, the decision table technique can be used to indicate what combinations of criteria should lead to which outcomes, thereby guaranteeing combinatorial completeness and consistency.

Checking and improving the quality of the regulations

Quality of regulations is an important asset, especially when regulations have to be applied in an automated environment.  Typical quality issues include:

- incompleteness:  missing conditions, cases or conclusions;

- inconsistencies:  equal situations leading to opposite values of one conclusion;

- redundancies:  unnecessary rules, with the risk of future inconsistencies;

- contradictions:  equal situations leading to incompatible conclusions;

- incorrectness:  unintended results or specifications.

When a written regulation exists, decision tables might be constructed in order to visualize the specifics of the regulation.  Transforming the text into the decision table representation for validation and verification purposes has traditionally been a major application area of decision tables.  The specific condition-oriented representation of the table avoids or detects these undesirable features.

Communication

Communicating text to different audiences is not easy if the terms and facts are not well-defined.  Text is difficult to read and often contains complex references, exceptions, etc.  The ability to focus on well-defined situations (rules or columns) has proven to be a valuable communication advantage of business rules and tables. 

Translation

Translation is another issue, because not only the terms have to be translated, but also the complex language formulations, such as:  if, and, except, unless, only, (etc.).  Translating the nuances of natural language from one language to another is a cumbersome and error-prone process.  In the European Union (for example), legislation and documents of major public importance or interest are produced in all twenty-three official languages (not including fifty regional and minority languages).  When the regulations are well-structured in rules or tables, translating the terms is sufficient, because the underlying logic is not language dependent. 

Impact analysis

Decision tables easily allow examination of the impact of changes in one part of a regulation on the total result.  The net effect of changing conclusions for some combinations of condition values, or including/excluding combinations for a specific conclusion is immediately visualized.

Generating test cases

Because all possible situations are represented, the decision table is an ideal source for the generation of test cases.  Instead of random testing, attention can be paid to the full coverage of a range of criteria, frequency of the cases, boundary value analysis, etc.

Restructuring the regulation

The business rules cannot only be used to verify or implement the regulation; they can also be used to redesign or reorder the text, refine and simplify the description, or change the fundamental structure.  Regulations are often described in the order in which they are conceived, but that is not necessarily the best order for understanding or implementation.

Specifically, after changes in the regulation, the decision table can automatically indicate and combine similar cases that lead to identical conclusions, thereby eliminating superfluous criteria for specific situations.  Therefore, if a new description of the regulation is desired, it can be derived from the decision table in a more orderly fashion by examining the application field of each of the actions and describing it in its most compact logical form.

Enforcing the regulations

Once completed, the business rules or the decision tables can be used as an execution mechanism directly, or they can be used to generate code, depending on the purpose of the system.  If the implementation is straightforward, maintenance of the regulation can be performed directly on the rules or tables.

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