Note 1 to entry: The mean failure intensity is related to instantaneous failure intensity z(t) as follows:
z ¯ ( t 1 , t 2 )= 1 t 2 − t 1 ∫ t 1 t 2 z(t) dt MathType@MTEF@5@5@+=feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbbjxAHXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeqabiGaciGacaqadmaadaqaaqaaaOqaaiqadQhagaqeaiaacIcacaWG0bWaaSbaaSqaaiaaigdaaeqaaOGaaiilaiaaysW7caWG0bWaaSbaaSqaaiaaikdaaeqaaOGaaiykaiabg2da9maalaaabaGaaGymaaqaaiaadshadaWgaaWcbaGaaGOmaaqabaGccqGHsislcaWG0bWaaSbaaSqaaiaaigdaaeqaaaaakmaapedabaGaamOEaiaacIcacaWG0bGaaiykaiaaykW7caqGKbGaamiDaaWcbaGaaGjbVlaaykW7caWG0bWaaSbaaWqaaiaaigdaaeqaaaWcbaGaaGjbVlaaykW7caWG0bWaaSbaaWqaaiaaikdaaeqaaaqdcqGHRiI8aaaa@5744@