Software Reliability and Infant Mortality Period of the Bathtub Curve

Abstract

In the past 30 years, numerous papers have been published in the areas of software reliability modeling, model validation, measurement, and practice [226]. Software has become an essential part of many industrial, military and commercial systems. In today’s large systems, software life-cycle cost (LCC) typically exceeds that of hardware, with 80 ∼ 90% of these costs going into software maintenance to fix, adapt, and expand the delivered program to meet the changing and growing needs of the users [589, p 305]. Compiling cost expenditures from all industries, in 1960 about 20% of the system’s cost was spent on software. That percentage has risen to 80% in 1985 and 90% in 1996 [385]. The investment in software increased even more dramatically for the military industry.