The lifetime model provides information about the lifetime, related limits and semantic of the lifetime of things like tools, material or machines.

Table 106 illustrates the model with two examples, showing the information that can be provided with the model defined in this chapter. The Value of the LifetimeVariable provides the current value. The EngineeringUnits Property and the relation of the Indication to a classification ObjectType provide the semantic. The StartValue and LimitValue Properties indicate the range of the Value.

Table 106 – Lifetime examples

Node	CertificateValidity	PartsProduced
LifetimeVariable	200	553
EngineeringUnits (M)	day	number of parts
StartValue (M)	365	0
WarningValues (O)	10	950
LimitValue (M)	0	1000
Indication (O)	TimeIndicationType	NumberOfPartsIndicationType

For the CertificateValidity example, the instance of the LifetimeVariableType defines the remaining validity of a certificate with a unit of days and a classification of TimeIndication. The Value specifies 200 days – the remaining validity of a certificate. The initial value is 365 days with a warning level of 10 days. The certificate is invalid when the Value is zero.

For the PartsProduced example, the instance of the LifetimeVariableType defines the produced parts in the lifetime with a classification of NumberOfPartsIndication. The Value specifies 553 parts. The starting value is 0 parts and it is possible to produce up to 1000 parts with a warning indication if the number reaches 950.