Business Rules
Introduction
- A business manages its own behavior through carefully selected and communicated rules
- A business introduces change by changing its business rules
- It is important for analysts to document these rules as they may affect information systems.
What is a Business Rule?
DEFINED: A business rule, is a statement that influences the behavior of an organization.
- It helps employees make decisions without having to ask a manager every time.
- An information system should support and enforce these rules.
- Good rules can help create new knowledge from existing information.
- There is a good chance these rules are not written down. So observe carefully.
How does that work?
EXAMPLE: Hotel has a rule that a customer can only check in if they have a reservation.
SITUATION: Customer arrives and says “I saw your vacancy and would like to check into a room.” Clerk responds, “Do you have a reservation?” Customer says “No.”
The above business rule must be satisfied. So the clerk responds “Just a moment while I make a reservation for you. Then we can get you checked in.”
Properties of a Good Business Rule
- ATOMIC - Cannot be decomposed without losing meaning. (No use of “and”, “or”, “but”.)
- DECLARATIVE – It explains “how to”, where and when the rule is imposed.
- PRECISE - Has only one interpretation.
- JUSTIFIED - Supports the objectives of the business.
- AUTHORIZED – Someone relevant to the business is empowered to create the rule. (i.e., the janitor does not have authority to create a rule on how orders are received.)
Business Rule Examples
- Everyone that appears to be under the age of 25 years needs to have their ID checked.
- We only ship complete orders.
- Before a work order can be completed, a customer’s information must be collected.
- Any customer that owes more than $5,000.00 cannot place new orders.
- All vehicles require a visual inspection for damage before being released to the customer.
Five Steps for Creating a Business Rule Collection
- Collect business ramblings
- Translate these ramblings into business rules
- Determine which of these rules are relevant to the project objectives
- Determine the data-rule dependencies
- Determine inter-rule relationships