SBVR_ — SBVR Issue on Authorizations / Dark World Assumptions

SBVR makes a 'light world' assumption about rules. In a 'light world', anything that is not expressly prohibited is assumed permitted. Business rule practice indicates that this choice is the appropriate one for the large majority of business problems.
Occasionally, practitioners may discover cases in which the opposite assumption is appropriate. In such 'dark world' circumstances, anything not expressly permitted is assumed prohibited. Such cases might involve use of, and/or access to, resources that are deemed especially sensitive, dangerous, scarce, and/or valuable. For that reason, it makes sense to grant permission for use and/or access explicitly. Such permissions are often called "authorizations".
SBVR does not offer any specialized support for authorizations. None is needed. Support for authorizations is accomplished as follows:
· A rule is expressed to declare that some general area of business activity is prohibited except where expressly permitted (i.e., 'dark').
· Specific advices of permission, qualified as appropriate, are given to indicate selective authorizations.
The following examples illustrate.
Example 1.
Fact type: person makes payment
'Dark' Rule Statement: A person may make a payment only if making the payment is expressly permitted for the person.
Advice of Permission Statements:
· A senior manager may make a payment.
Note: This rule statement could also be expressed: A person may make a payment if the person is a senior manager.
· Jane Smith may make a payment.
Note: This rule statement could also be expressed: A person may make a payment if the person is "Jane Smith".
Example 2.
Fact type: ice road is used by vehicle
'Dark' Rule Statement: An ice road may be used by a vehicle only if using the ice road is expressly permitted.
Advice of Permission Statements:
· An ice road may be used by a vehicle if the ice road is north of the arctic circle.
· The ice road with the name, Yukon 12,000 Foot Lake Road, may be used by a vehicle.
· An ice road may be used by a vehicle if the average temperature at the southern-most point has been below 0o C for at least 5 days.

Add the new subsections below to the end of Clause 12.
Note that the material below incorporates the material agreed for Issue 10562, and this Resolution indicates the placement of that material.
Note also that this Resolution subsumes and completes Issues 10505 and 10506.