Back to Basics 4 – Levels in Oracle Policy Modeler
One of the things that students struggle with in the Oracle Policy Automation Essentials class which was offered by Oracle University for OPA version 10, but never upgraded to version 12 (something which I struggle to understand, and I will freely admit so do the customers I meet, to the point where I am obliged to deliver version 12 Essentials using custom environments and complicated workarounds from an administrative perspective) is the concept of Levels in Oracle Policy Modeler in writing rules.
Perhaps the term “levels” is the problem. Anyway, here we go
Basic Idea #4 – Rules written in Word can express logic in a hierarchical fashion, for example
If it helps get a grip on this hierarchical layout, consider the following alternative :
In both cases the structure of the rule is hierarchical, in the second case each subordinate conclusion is presented separately. In the first instance they are all included in the first premise, as nested levels. Notice the “OR” in the first example, and how it is yellow in color, because it relates to the comparison between the two yellow components – more correctly, it compares two level one conditions, which themselves have level two conditions. It is a common issue for beginners to misplace the “OR” or to color it with the wrong level of nesting.
There are upsides and downsides to both approaches, and there are plenty of other criteria (mapping to source documentation, readability, ease of location and display in interviews to name just a few) that may drive how you write these nested structures. But as a new starter, considering that Levels in Oracle Policy Modeler show the proof needed to prove the higher level, can provide an easy to remember way to correctly nest your Word text in your Rule Projects in Oracle Policy Modeler.
Have a nice day.