Title: A constrained quadratic spline as a model for the cumulative hazard function

Authors: Vasiliy V. Krivtsov, Ilya V. Kolmanovsky, Timothy P. Davis

Addresses: Ford Motor Company, Dearborn, Michigan, USA. ' Ford Motor Company, Dearborn, Michigan, USA. ' Ford Motor Company, Dearborn, Michigan, USA

Abstract: Probability distributions traditionally used in reliability analysis (e.g. exponential, Weibull, lognormal, normal, gamma and inverse Gaussian) do not always provide enough flexibility to model real-world lifetime data. Considered in this paper is a quadratic spline with a single free knot as a model of the cumulative hazard function for increasing failure rate distributions. A parsimonious (essentially closed form) solution with a simple numerical search is proposed for estimating spline parameters. Automotive warranty data examples are discussed as an illustration.

Keywords: cumulative hazard function; spline models; quadratic spline; automotive warranty data; automobile industry; reliability analysis.

DOI: 10.1504/IJRS.2008.021062

International Journal of Reliability and Safety, 2008 Vol.2 No.3, pp.170 - 178

Published online: 01 Nov 2008 *

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