Total Quality Management: the Future of the Reliability Metaphor for Aging

A loose **classification** of longevity theories would separate the functional theories — how senescence proceeds in the individual organism — from the teleological theories, which seek to explain why a given pattern of senescence ought to be so, usually from the evolutionary perspective. We focus here on the loose class of functional theories allied to engineering reliability theory. The link between the wearing out of mechanical devices and the senescent decline of organisms is as hoary as it is hackneyed, but it is only in recent years that this vague analogy has budded into specific theories. In particular, Koltover (1981,1982,1997), Witten (1983,1984,1985), and Gavrilov and Gavrilova (1991, 2001) presented elementary stochastic models that aimed to reproduce the Gompertz exponential increase in mortality. Koltover (1997), who suggests that the reliability metaphor in biology was extensively studied in the 1970s and 1980s in the Soviet Union, states the case as follows: Apart from the formal fitting to the mortality data, the theory of reliability can also be used as a guideline for searching for realistic mechanisms of aging. It is possible for a complex system to exhibit global programmable modes of failures that are not associated with local subsystem failures. Gavrilov and Gavrilova (2001) suggest that [Reliability theory] offers a promising approach for developing a comprehensive theory of aging and longevity that integrates mathematical methods with biological knowledge including cell biology[,. . . ] evolutionary theory [,. . . ] and systems repair principles.