ABSTRACT
It has been recognized that despite its considerable significance (notional as it may be) (see Figure 1) [1], the lifetime concept resists explicit modelling and numerical evaluation of its ‘absolute’ value. However, such a concept may be much easier to apply in comparing various design, exposure and maintenance circumstances; for such a relativistic use, absolute lifetime values are no longer necessary and the concept exhibits its potentiality without liability problems eventually produced because of its large uncertainties.
