In the previous article, Who, What and How of a Business analyst, we examined the role and responsibilities of an IT Business Analyst. In this article, we shall focus on the basic concepts of business rules. In the upcoming articles, we shall investigate what business rules mean to a Business Analyst and how they lead to the transformation into a Business Rules Analyst. A lot of research has been pursued by eminent experts in the field. In this article, we shall learn the basic principles of business rules. So, let us begin with answering the question “What is a Business rule?”
In an organization, business logic may apply across multiple departments and/or projects and/or applications. This business logic must be traceable and should not be lost with either data or application specific functionalities. When following a business rules approach, business rules include the specification of this business logic in natural language. They are stated in declarative terms which widens the audience that deal with business rules, as opposed to being procedural which restricts their usage to the technical audience and a specific automation platform. A business rule is a statement that describes a business phenomenon and asserts a behavior that influences the business. A business rule defines an aspect of the business. The real life interpretation of business rules includes definition of terms, constraints, derivations and facts relating to each other.
In purely business-driven initiatives, business rules are identified as part of business strategy, tactics and planning, which occur prior to the kickoff of a systems development project. But, for business rule projects that begin as systems development projects, business rules are most often identified during analysis and requirements gathering. Multiple business rules might impact an artifact or the same business rule may reference multiple artifacts. Hence, scoping and identification of business rules is a crucial step in determining the success of a project.
A business rule may be written in a simple sentence or may be expressed as a complex statement cross-referencing multiple artifacts. The three basic ways of expressing business rules are:
- Natural expression: a simple, comprehensible natural language statement which expresses the core business phenomenon.
- Logical expression: an “if – then – else” statement that is suitable for non-technical business-domain experts.
- Formal expression: a format that is suitable for a wide variety of rule-based systems and programming mechanisms.
A business rule should not address any aspect of its implementation; it is a firm assertion of a business phenomenon. A business rule should not contain another rule in itself and should address only one concept. These characteristics, atomicity and cohesiveness respectively, ensure reusability. A business rule must be precise. It should not lead to any ambiguity. A business rule must be consistent across all processes, departments and applications. Business processes transform over time. Hence, a set of rules may alter with time to reflect evolving company directions and objectives. Business rules should be adaptable to any possible change. Business rules must be written in a fashion that they can be validated/verified for their trueness. Various approaches may be adopted to do so, rules may be posted on the web where the business may verify them or updates to rules discussed over regular meetings with the business may be applied to the rules.
Various classifications have been proposed by the experts in the field like Knowledge Partners Inc., the Business Rules Group, USoft Inc., Versata Inc., Ronald Ross, C.J. Date, to name a few. The following is a classification that encompasses the major types of business rules:
- Constraint: expresses an unconditional circumstance that must be true or not true for the business event to complete with integrity.
- Inference: tests conditions and upon finding them true, establishes the truth of a new fact.
- Computation: provides an algorithm for arriving at the value of a term.
- Validation: defines data element constraints or UI element constraints.After being scoped, classified and expressed in an enterprise based standard, business rules must be stored in a central repository that is readily accessible and revisable. This storage should aid in nurturing and managing business rules.
A simple statement that encompasses the business behavior without any implicit meaning or ambiguity exemplifies a well written business rule. For e.g. the criteria to apply for a credit card could be a business rule as: “A customer must have a FICO score of at least 550 to apply for XYZ credit card”. This is a business constraint expressed in natural language and is atomic, explicit, adaptive and verifiable.
Business rules are a reflection of businesses. Or, even more correctly, the business will turn out to be a reflection of the business rules that are established. Business rules govern and drive the business processes. It is crucial that IT functions as a business within a business for the success of an organization in the modern era. Business rules play a pivotal role as they serve as an effective communication channel to business analysts for transmitting the business expectations to technical experts.
