Consecutive k-out-of-n:F Systems Have Unbounded Roots

Abstract

This article is studying the roots of the reliability polynomials of linear consecutive-\textit{k}-out-of-\textit{n}:\textit{F} systems. We are able to prove that these roots are unbounded in the complex plane, for any fixed $k\ge2$. In the particular case $k=2$, we show that the reliability polynomials have only real roots and highlight the closure of these roots by establishing their explicit formulas. We also point out that in this case, for any fixed \textit{n} the nonzero roots of the reliability polynomial are distinct numbers.