CV-2x3-121 (aka CV-06-121)

Decomposed elements shall have a maximum of 1 level decomposition depth [withdrawn 07-10-2011]

Based on          IFC2x3

Initiator            ISG Meeting-Munich

Effects              Extended Coordination View

Date                    2006 05 05


Update 2011-10-07:

This implementer agreement has been withdrawn with immediate effect. The IFC2x3 Coordination View 2.0 compliant applications shall support a decomposition depths of more than one level.

    NOTE:  In order to avoid potential endless recursions, it is agreed to end import routines after the 9th level of decomposition.

See also agreements CV-2x3-119, CV-2x3-120

Outdated agreement:

The IFC specification allows all subtypes of IfcBuildingElement (and other) to act as a container entity, i.e. to be a decomposed element having parts. This is expressed by an IfcRelAggregates relationship entity pointing to the container with RelatingObject and it referenced by the inverse attribute IsDecomposedBy. An example is a roof, containing two roof slabs:

    *IfcRoof <--RelatingObject-- IfcRelAggregates --RelatedObjects--> IfcSlab (PredefinedType=.ROOF.)

The following agreement is made:

    *The parts contained within an element container shall not be containers by themselves. I.e. the decomposition hierarchy shall only have 1 level depth.

Example: The roof slabs in the roof example above shall not be aggregated into rafters and claddings (as this would be a 2 level deep decomposition

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