Practical aspects of modelling of repairable systems data using proportional hazards models

Cox's Proportional Hazards Model (PHM) has been widely applied in the analysis of lifetime data. The model is semi-parametric, so that weak assumptions are made about the form of the hazard function. There have been medical developments of this model which have aided studies of repairable systems. A review of the practical use of this PHM model is given and particular attention is paid to the use of diagnostic statistics and graphs. Illustrations are given using field data from the semiconductor and electrical industries, and repairable data will be illustrated by data from the hydrocarbon industry. (C) 1997 Elsevier Science Limited.