Well, here of course is something so basic that you would have thought most people would know what they should be.
But, like the quip goes, Life is stranger than Fiction !

I have been reading Martin Fowler’s “Patterns of Enterprise Application Architecture” and the first thing that he attempts to do is to try and define what is an Enterprise Application. The first 100 pages at least are a very good read, what follows later might be of interest only to the hard core Patterns Bigots!

I’ll try the same approach. One of the things that I like to tell my team members who find it difficult to understand what Business Rules are, and how to capture them while developing their Apps is to try and imagine the Business application Minus the software.
The Rules that remain after you remove the software are the Rules of the Business.Well, there you have it, those are your Business Rules, rules that run the Business.
Enterprise Applications involve a lot of Data & Information Processing Processing. IBM some time had put out a news that they had moved online all their contracts with their partners.

All those who even some experience with contracts, SLA’s, License agreements and the like know how tricky these can get. There will be so many variations that you will see in these that automating Contract Validation & Processing must have been some exercise.
I have no clue how IBM implemented their system, but this is one classic example of Rule Enabling your application.

So coming back to the “What are Business Rules” question, here are some of the things that I have seen, heard and realized.

1. Not every If Then is a Business Rule
2. You have Process Rules (and/or system Rules). These are the rules of your software system. Like for example, a user cannot be logged in through 2 sessions at the same time.
3. Business Information MUST be Loaded, Modified and created and Persisted in any Business application.
4. While Loading & Saving Business Data, Process/System rules apply.
5. Correct, precise information is of the utmost value in any Business
6. Business Rules will typically apply when ever you are attempting to create new information or when you are attempting to modify existing information

Now, identifying Business Rules is one problem, but identifying Business Rules that you can externalize is something else. I will talk about that some other day, in another post.