IfcServiceLifeFactor

Definition from IAI: An IfcServiceLifeFactor captures the various factors that impact upon the expected service life of an artefact.

> HISTORY: New entity in IFC 2x2

### Use Definitions

Note that each instance of IfcServiceLifeFactor may have a name that describes the form of impact that the factor has on the service life. Because there is a significant list of such potential impacts, they are not explicitly collected together into an enumeration. In order to name an instance of IfcServiceLifeFactor, the inherited Name attribute should be used.

Within the IFC specification, any number of service life factors may be allowed to impact upon the service life of an artefact. In many cases, it is probable that the ISO standard that specifies good practice for service life consideration will be applied.

Within the ISO standard, there are seven defined (named) service life factors that may be applied to an IfcServiceLife. These are captured in the IfcServiceLifeFactorEnum (together with a user defined capability). Each factor can have three values that define an upper, lower and most used (or median) value.

One or more instances of IfcServiceLifeFactor can be related to an IfcServiceLife through the IfcRelDefinesByProperties relationship class.

EXPRESS specification:

ENTITY IfcServiceLifeFactor
SUBTYPE OF ( | IfcPropertySetDefinition);
PredefinedType | : | IfcServiceLifeFactorTypeEnum;
UpperValue | : | OPTIONAL IfcMeasureValue;
MostUsedValue | : | IfcMeasureValue;
LowerValue | : | OPTIONAL IfcMeasureValue;
WHERE
WR31 | : | NOT(PredefinedType = IfcServiceLifeFactorTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType);
END_ENTITY;

Attribute definitions:

PredefinedType | : | Predefined service life factor types from which that required may be set.
UpperValue | : | Upper of the three values assigned to the service life factor.
MostUsedValue | : | Most used of the three values assigned to the service life factor.
LowerValue | : | Lower of the three values assigned to the service life factor.

Formal Propositions:

WR31 | : | The attribute UserDefinedFactor must be asserted when the value of the IfcServiceLifeFactorEnum is set to USERDEFINED.

Inheritance graph

ENTITY IfcServiceLifeFactor;
ENTITY IfcRoot;
GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;
ENTITY IfcPropertyDefinition;
INVERSE
HasAssociations | : | SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcPropertySetDefinition;
INVERSE
PropertyDefinitionOf | : | SET [0:1] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition;
DefinesType | : | SET [0:1] OF IfcTypeObject FOR HasPropertySets;
ENTITY IfcServiceLifeFactor;
PredefinedType | : | IfcServiceLifeFactorTypeEnum;
UpperValue | : | OPTIONAL IfcMeasureValue;
MostUsedValue | : | IfcMeasureValue;
LowerValue | : | OPTIONAL IfcMeasureValue;
END_ENTITY;