SBVR11 — Coexistence approach to SBVR

According to our observations, more than 95% of all business applications operate under the closed world assumption and the state of affairs interpretation. In order to give other approaches (standards) the option to work with SBVR, it is proposed to offer the following: for each fact type one of the following combinations can be selected:
1. Closed world assumption; state of affairs interpretation
2. Closed world assumption; actuality interpretation
3. Open world assumption; state of affairs interpretation
4. Open world assumption; actuality interpretation.

For convenience it is recommended to add the following four meta fact types:

1. The population of all fact types in <conceptual schema> is considered <closed_or_open>
2. The population of all fact types in <conceptual schema> is considered <state-of-affairs_or_actuality>
3. The population of <fact type> is considered <closed_or_open>
4. The population of <fact type> is considered <state-of-affairs_or_actuality>

Note that a fact type overrides a conceptual schema specification. Note that there is a business rule that for each fact type it holds that it can have only one value of closed_or_open and one value of state-of-affairs_or_actuality.

SBVR works with all business applications that are based on business vocabularies and rules, regardless of open/closed assumptions and regardless of whether fact models are interpreted as representing the real world or as representing hypothetical worlds.
Closed world assumption – SBVR supports both open and closed world assumptions. Wherever there is a desire to assert that all fact types in a given conceptual schema are closed (or open), that proposition can be formulated with existing SBVR concepts using universal quantification. For example, for a conceptual schema C:
Each fact type that is in C is closed in C.
Any default selections of open or closed by tools that create conceptual schemas are a matter for tool builders to decide and are not a subject of the SBVR specification.
Characterizing a fact type as open or closed independently of any conceptual schema or fact model is inappropriate because the same fact type can be in multiple conceptual schemas. A fact type is a meaning. Since it is logically possible that the same meaning is in multiple conceptual schemas created by different people for different purposes, it is impractical to assume that anyone would know whether closure is universal. Therefore, no new fact type characterizing fact types as open or closed will be added.
However, any tool can certainly have defaults or allow defaults to be set regarding closure for the conceptual schemas that are created by that tool.
State-of-affairs interpretation – SBVR defines ‘fact’ to be “proposition that is taken as true”, not as “proposition that is true”. A fact is a proposition that is taken to be true in the world that is the subject of discourse, whether that world is real or hypothetical.
Any tool can have its own default behavior with respect to assumptions about possible worlds. Defining such defaults is outside of the scope of the SBVR specification.

Disposition: Resolved with NO CHANGE