From an engineering point of view, there has been some work on the application of reliability theory to aging, though not to the point where your question can b

From an engineering point of view, there has been some work on the application of reliability theory to aging, though not to the point where your question can be answered using this approach: https://en.wikipedia.org/wiki/Reliability_theory_of_aging_and_longevity https://en.wikipedia.org/wiki/Reliability_theory_of_aging_an... http://www.ncbi.nlm.nih.gov/pubmed/20469937 http://www.ncbi.nlm.nih.gov/pubmed/20469937 Immune system aging is an important component of age-related frailty, and probably also accounts for the rising number of senescent cells and higher cancer risk. It isn't as simple as a dearth of cells, however. It is more of a complex configuration/whole-system failure in which rate of cell replacement is just one variable contributing to the bad state endpoint. See for example: https://www.fightaging.org/archives/2006/12/when-and-how-does-the-decay-of-your-immune-system/ https://www.fightaging.org/archives/2006/12/when-and-how-doe... https://longevityandhealthspan.biomedcentral.com/articles/10.1186/2046-2395-2-8 https://longevityandhealthspan.biomedcentral.com/articles/10...