Abstract
The region of useful redundancy for a k-out-of-n system of identical components is the interval in component reliability for which the reliability of the system is better than that of a single component. A table for the lower boundary of that region is presented for n ≤ 56. The table is compiled with a high precision and a minimal round-off error by using a highly efficient algorithm for computing the k-out-of-n system reliability. Certain symmetries and limiting values are noted, thereby allowing a cutting of the number of entries actually listed in the table by more than one half. If the component lifetime is assumed to be exponentially distributed, then the table entries can be used to compute the point that divides the time axis into intervals of a short mission and a long mission for k-out-of-n redundancy.