Events, Business Rules and Facts: Not the Same!In current discussions, I find people are not being careful about the difference between “event” and “business rule”. An event is something that happens. A business rule gives guidance. An event is an event and a business rule is a business rule. A business rule can produce a fact (‘automatically’) that an event has occurred. But that fact is not the same as the event or the business rule either. To see the whole picture, you need to relate 3 distinct things. The following example Illustrates. The Event …
A credit card is used to purchase something. The purchase happens in the real (or virtual) world.The Business Rule …
A credit card event must be considered potentially fraudulent if all the following are true:
- The credit card is used to purchase a very low value item.
- The credit card is used to purchase a very high value item that is easily resellable.
- The second purchase occurs after the first purchase by less than an hour.
“Credit card event is potentially fraudulent.” This fact is what we know (or infer) about what happened in the real world.These are three distinct things representing how what we know is derived from what happens in the world around us. P.S. This position represents the SBVR view.