MTTFFn - Sigma Knowledge base Browser

appearance as argument number 1

(instance MTTFFn UnaryFunction)	Mid-level-ontology.kif 34549-34549	Mean time to failures is an instance of unary function
(documentation MTTFFn EnglishLanguage "(MTTFFn ?CLASS), mean time to failures is the predicted elapsed time, based on statistics of its past performance, when a NonRepairable Device or component is replaced after a failure during normal system operation. [Wikipedia] Note that the argument for MTTFFn is a Class of the Device. For an instance of Device use (TimeToFailureFn ?D). ")	Mid-level-ontology.kif 34550-34554	Mean time to failures is an instance of unary function
(domainSubclass MTTFFn 1 Device)	Mid-level-ontology.kif 34558-34558	The number 1 argument of mean time to failures is a subclass of device
(range MTTFFn TimeMeasure)	Mid-level-ontology.kif 34559-34559	The range of mean time to failures is an instance of time measure

appearance as argument number 2

(termFormat EnglishLanguage MTTFFn "mttf")	Mid-level-ontology.kif 34555-34555
(termFormat EnglishLanguage MTTFFn "mean time to failures")	Mid-level-ontology.kif 34556-34556
(format EnglishLanguage MTTFFn "The MTTF of %1")	Mid-level-ontology.kif 34557-34557
(relatedInternalConcept MTBFFn MTTFFn)	Mid-level-ontology.kif 34560-34560	Mean time between failures is internally related to mean time to failures
(relatedInternalConcept MTTRepairFn MTTFFn)	Mid-level-ontology.kif 34561-34561	Mean time to repair is internally related to mean time to failures

antecedent

(=>
    (and
        (equal
            (MeasureFn ?X HourDuration)
            (MTTFFn ?CLASS))
        (instance ?D ?CLASS)
        (equal
            (MeasureFn ?Y HourDuration)
            (TimeToFailureFn ?D))
        (inList ?Y ?L))
    (equal ?X
        (AverageFn ?L)))

If equal X hour duration(s) and The MTTF of Y, Z is an instance of Y, equal W hour duration(s) and The time to failure of Z is HourDuration, and W is a member of V, then equal X and the average of the numbers in V