A direct algorithm for computing reliability of a consecutive-k cycle

A consecutive-k cycle is a circular system such that the system fails if and only if any i consecutive components all fail. Reliabilities for consecutive-k cycles are usually computed by recursive equations. However, most recursive equations proposed so far for the cycle involve reliabilities for consecutive-k lines, requiring two passes where the first pass computes only the line reliabilities. A recursive equation involving cycles only is proposed that is simpler in form but much harder to understand on intuitive grounds. Another advantage is that the proposed cycle recursion has the same form as a line recursion previously proposed. Thus a uniform treatment of lines and cycles is possible. This uniform approach is used to obtain some explicit solutions of both line and cycle reliabilities for 2⩽k⩽4