Introduction

The theory of Reliability and Life Testing has its roots in the research into the performance of engineered systems that was spawned by the applications arising in the second World War. An example of early studies of reliability issues is the work of Abraham Wald who, as a member of the heralded Statistical Research Group at Columbia University, treated the problem of estimating the vulnerability of aircraft used in WWII from data on “hits” taken by the planes that returned from various missions. Wald’s work led to the addition of reinforcement of particularly vulnerable sections of the fuselage which ultimately led to a higher rate of returning aircraft. Wald’s research on these problems was declassified in the late 1970s and is described in detail by Mangel and Samaniego [55].