I was getting one of my developers today to read through some VB code that one of our sales guys wanted deciphered. The task was to read a VB class, extract the business rules, business terms out of that class, then model the rules it using QuickRules.NET.

I was watching how long it took for my developer, who is a pretty bright young fellow. The yellow column are the results out of the exercise. The turquoise color columns are my projections.

Analysis Model

Plot of Model

The three sets of Column Plots are for 500, 5000 and 50000 lines of Code, from the left to the right respectively

Assumptions

1. The number of business rules will increase linearly with the number of lines of code in an business application
2. The time to extract/understand rules will increase non-linearly.For 3-5 classes, the formula adds a 50% buffer(2*10*2). For 50000 lines of code, the formula adds a 100% buffer (30*10*3).
3. The buffer is required because the time to extract rules from code will not increase linearly, but exponentially, which explains the numbers that I have in the last row. That is because with more code, complexity will increase.
4. The last entry, Time to Understand rules was the time taken by an independent developer to understand the newly extracted rules. 20 minutes was the reported time, but I guess, it must have been lower.The assumption is that it follows the same pattern of increase as for the rule extract and code understand effort.

Model Interpretation

1. It costs 10 times more to understand business rules embedded in code than when business rules are externalized using a Business Rules Engine and a BRMS
2. Another way to look at it is that it can take upto 10 times more time to make changes in an business rules, if they are embedded in Code, and NOT externalized.
3. You can say that externalizing business rules using a BRMS decreases the complexity of the business logic layer by a factor of 10. The reduced complexity factor will mean that the time for testing business rules changes will be down by a factor of 10. This means a reduction by 90%
4. This in turn means that your Change Management Costs will come down by a factor of 10. This means a reduction by 90%
5. This in turn means that the chance that an opportunity will be executed will increase by upto 10 times
6. If Business Rules remain locked within IT, they will lead to an increased Business Risk
7. Your can read the Extreme Mortgage Story for a true story of how a company created a 1 Billion USD Opportunity in under 6 months

Questions for you to Reflect

1. Are you building a new business application?
2. Are you looking to enhance your current business application to take advantage of a new opportunity?
3. In both the above cases , Externalizing business rules can save you upto 90% of your change management costs