On a recent client’s project, we were asked to help in the effort of creating a system to automate much of the current manual processes.  In order to capture the requirements this also meant that we were documenting the business rules that were currently being used.  When I started the project, I did not have a complete understanding of how a business rule was different than a requirement statement.  I found that I was constantly getting mired in my confusion between the two. 

From my research I did find one Wikipedia article to be particularly helpful, but I simplified that advice even further.  From my reading  and experiences, I created the following four guidelines to help me determine if a statement was a business rule that would need to be represented within the new system and should described within my functional requirement statements. 

 1:  A business rule is about the how to run the business and not about a system, or set of systems.  If you removed all the systems and system platforms, the rule would still important to the business operations.  Business rules are about people doing business activities, to achieve business goals not interacting with systems.  A very simple rule that is used every day is “No shoes, no shirt, no service” a person can read this rule, and know what actions they are to perform.  A functional requirement would be to support the “No shoes, no shirt, no service” rule within the system.

2: Does the rule provide enough information for a business person to make a decision, or a series of decisions?  If a business person uses the rule to make a decision, then it’s a business rule.  The rule exists in order to operate the business.  A business person could easily read the rule and understand how they are to conduct business.

3:  Business rules are owned by the business.  A business person must be able to change, or modify rules as they identify changes.  For example, a rule may be that “Only people between the ages of 25-35 may open a customer account”.  A system requirement could be written to support that age constraint.  The rule however, is owned by the business and could be changed at any time based on business objectives. 

4:  A business rule must place some type of constraint or requirement on the way that business is conducted.  For example, “Only customers with an approved line of credit of $1,000 or more may place orders within the corporate product catalog”.  This rule shows how customers are constrained and prevented from certain operation, or activities.  A system requirement might be necessary to support multiple rules which constrain customer activities.  The business rules define the constraints.

by LAnderson

Do you have feedback on how to determine a business rule?