Total Time on Test Plots

Abstract

In the 1970s the total time on test (TTT) plot, and its theoretical counterpart, the scaled TTT transform, was presented by R. E. Barlow et al . as a tool for model identification based on data representing lives of nonrepairable equipment. It has been used when analyzing different aging properties, optimising replacement policies and studying test statistics. Generalisations of the TTT plot have also been used for analysis of data from repairable units. It has also been suggested as a tool for the selection of active factors in design of experiments. In this paper we give an overview of TTT plotting and its practical and theoretical applications. A wide range of references are suggested for further reading.