Business Rules Cheat Sheet by tnbergeman

Business rules enable the business to make better, more consistent decisions in day-to-day business activity

Reduction
Elicit­ation
RuleSpeak
Decision Tables
Validation
Management

Business Policy: No new home-owner insurance during storm threats.
Business Rule: A home-owner policy must not be issued for a home within the 4-day cone of uncert­ainty for a storm.

Requir­ement: Provide a feature to handle electronic funds transfer.
Business Rule: An employee expense reimbu­rsement must be processed through electronic funds transfer.

Look for:
- Repetitive behavior in tasks
- Operat­ional decision points
- Non-tr­ivial areas of work
- Business rules embedded in code

Conflict - rules contradict each other
Subsum­ption - the rule is already covered by another
Redundancy - rules state the same thing essent­ially
Similarity - rules that are potent­ially identical but have incons­istent specific qualit­ifi­cations

Comput­ation Rules: "The net profit must be computed as the gross sales amount minus the overhead amount­"
Derivation Rules: "A customer must be considered inactive if the customer has not placed an order in the past 3 years"
Decision Rules: Knowing how to decide something - Decision Table

Behavioral Rules: Rules that people can violate; "A customer must have an assigned agent if the customer:
 has placed an order, and
 is not inacti­ve."­

i.e. "Is the applicant eligible for auto-i­nsu­ran­ce?­". For each major decision:
 Define business rules that apply to all sub-de­cisions of the major decision
 Estimate 5-10% of overall business rules within the major decision
 Estimate one-week effort per major decision (subject to scope)

i.e. "Has the applicant given acceptable evidence of insura­nce­?" For each sub-de­cision:
 Define business rules that apply to all cases for a sub-de­cision first
 System­ati­cally develop the business logic for each case within each sub-de­cision
 Estimate an average of 2 weeks per sub-de­cision (subject to scope)
 If steps 1-3 are done correctly, project team members can work on cases or sub-de­cisions in parallel

1. Determine enforc­ement level (strictly enforced, guideline, etc)
2. Determine what messaging is needed in case of a breach
3. Determine business response in case of a breach

Always clearly define each and every part of a business rule that is not cut and dry;
"Kids must be in bed by 11:30 on school nights."
1. Time-o­f-day rule: Time-o­f-day is determined by parents' watch
2. In-bed rule: "­In-­bed­" must be interp­reted to include all of the following: Electr­onics off, lights off, you are in your own room/bed alone, you are washed up.
Continue with School­-night rule, Washed-up rule, etc. until all remaining terms are derivable or comput­able.

Remember to assign terms instead of keeping quanti­tie­s/a­mounts in the business rule, i.e. "­Cus­tomers must not be able to place more than 3 orders per day." becomes "­Cus­tomers must not be able to place more orders than the maximum number of orders per day."

Two rules: "A customer may have access to the warehouse only during regular business hours."­ and this exception "A gold customer must have access to the warehouse 24/7."
Become: "A non-gold customer may only have access to the warehouse during regular business hours; gold customers have access 24/7."

Use when you can identify a pattern but cannot create a comput­ational formula.
1. List the potential outcomes
2. List the consid­era­tions (what do we have to consider in making this decision?)
3. Define the individual cases (what are the actual different inputs?)
4. Define a default and place at the top of the table