What is "business rules"? Please explain with some example.
Businees logic is core logic to build the application for the requirements.
But what is business rules?
Answer
BRMS = a set of tools to edit and execute business rules
JRules = a BRMS solution like JBoss rules, Blaze advizor, and much more
You want to use BRMS to externalize the business logic from the application.
It is the same as a database which is there to externalize data.
A business rule is atomic and represent a part of the business logic.
E.g:
"if the age of the applicant is less than 18 then reject the application"
BRMS is composed of:
- a rule repository (filesystem or DB)
- a developper (like Eclipse) and a business user (non technical) interface (web)
- an environment to execute the rules
You use BRMS in order to create a Decision Service.
It can be "callable" in J2SE, J2EE, EJB, Web Service, MDB, ...
Hence the businees rules which are part of a Decision Service (ruleapp/ruleset in JRules) can be called by various application.
The real advantage of a Decision Service.
Think of it like when a BPM needs to make a decision, rather than code the condition and actions in the application itself then make a call to a DS to have the answer, hence the decision.
It will takes you nothing more than 1 hour to create a dummy DS and call it from a BPM application such as Tibco Business Works.
Another definition of Business rules is that it is the result of a business policy implementation.
Business policy: "A good customer should be reward for the end of the year"
The Business Analyst job is to extract the rule from this statement and hence end up with rules like that:
"if the status of the customer is GOLD and the amount of the shopping cart of the customer is greater than £5,000 then set the status of the client to PLATINUM"
When you create the rule you have to ask yourself a lot of question like:
What about SILVER and BRONZE status? Are all the threshold covered by rules? and so on...
A Decision Service can potentially contain several thousands of business rules
For example: Some for validation, some for eligibility, some for quotation and so on...
Hope it helps