“…Redundancy optimization problems can be divided into three classes: dynamic programming, integer programming, and heuristic methods. Several heuristic algorithms (Shi [3], Sharma and Venkateswaran [4], Aggarwal et al [5], Aggarwal [6], Nakagawa and Nakashima [7], Gopal et al [8,9], Chen et al [10], Sharma and Misra [11], Prasad et al [12], and Coolen-Schrijner et al [13]) have been developed for redundancy reliability optimization problems which search for the solutions only in feasible regions. The heuristic method given by Nakagawa and Nakashima [7] obtains the solution by repeatedly applying a redundant component at a stage that has the greatest value of a 'weighted sensitivity function'.…”