A safer Decision Table example
While our Decision model is very powerful, in its current form, it’s very dangerous. It recommends milk-based products to lactose-intolerant customers. Even worse, it could be recommending products with nuts to people with severe allergies.
We need to fix this. Our first thought is to update the Product Recommendation decision table. It is possible to write our rules to do this but it is also very likely that such an important decision will somehow get lost in all the rules we are writing. If not now, somebody in the future could forget this important rule with potentially fatal consequences.
Far better to chain our decision nodes to highlight in our Decision Model how important this health check rule is. Figure 4.25 is an example of how we could design this:
Figure 4.25 – A safer product recommendation service
This model is downloadable as 04_Product_Recommendation-collect.dmn but is simple to recreate...