Shortcut rules are a type of application rule used to capture implicit logic which does not automatically flow from source rules. Shortcut rules only participate in inferencing and do not participate in the question search, and are therefore useful in streamlining interviews.
Understand how shortcut rules work
To understand how a shortcut rule works, consider the following two statements:
The claimant has lived in America for more than 50 years
The claimant has lived in America for more than 20 years
The second statement must be true if the first is true. On the other hand, the reverse is not the case, although it might be true (ie it is not necessarily false).
This type of situation needs to be captured where rules are used in a software application, to avoid situations where the application asks redundant questions (just imagine answering that you had lived in America for 50 years, then being asked if you’d lived there for 20 years!).
If we try to model this logic using our default rule format, we would have the following rule:
the claimant has lived in America for more than 20 years if
the claimant has lived in America for more than 50 years
When compiled, this rule would automatically be given an alternative conclusion. An alternative conclusion for this rule would not be correct, however, as it is not necessarily the case that the claimant has not lived in America for 20 years just because they have not lived there for 50 years.
Assume the rule did not have an alternative conclusion. While investigating the conclusion, the question search would traverse this rule and try to prove the condition. Assuming that no other rule proved the conclusion, if the condition returned false, there would be no alternative conditions to investigate, resulting in the goal being exhausted.
Instead, we can define this rule as a shortcut rule and it will then provide the required logic. As a shortcut rule, if the condition is set to a value of true following the operation of the question search on other rules, inferencing operates to set the value of the conclusion attribute. If the value returned is not true, this rule will not fire, and the conclusion attribute will not be set. Alternative conclusions are not set for shortcut rules.
It is possible for attributes proved in shortcut rules to be interrelated in a logical loop, because no alternative conclusions are set and because they are not traversed by the question search. So in addition to the shortcut rule above, it is also possible to have the following shortcut rule:
the claimant has not lived in America for more than 50 years if
the claimant has not lived in America for more than 20 years
NOTE: Shortcut rules should only be used when you can prove a base level attribute before it is asked.
To write a shortcut rule in Microsoft Word, click the Shortcut Rule button on the Oracle Policy Modeling toolbar (or press F7) to add a shortcut rule template.
Essentially, the only difference between the format of a shortcut rule and a standard rule is that the rule has an additional paragraph above it which uses the Rule Type style and reads "shortcut rule". Lacking this heading, the rule will be given an alternative conclusion, and will participate in the question search, causing goal exhaustion. The rule template also leaves a line for you to provide a rule name.
For example,
shortcut rule
the claimant has lived in America for more than 20 years if
the claimant has lived in America for more than 50 years
It is also possible to use rule tables for writing shortcut rules. For example,
shortcut rule
the claimant lives in Australia true the claimant lives in Sydney true the claimant lives in Canberra false the claimant lives in London
NOTE: You must not include an alternative conclusion in your rule table for a shortcut rule.