This paper considers the optimal standby component sequencing problem (SESP) for 1-out-of-N: G heterogeneous cold-standby systems. Given the desired cold-standby redundancy level and a fixed set of components, the objective of the optimal system operation scheduling is to select the initiation sequence of the system components so as to minimize the expected mission cost of the system. Based on a discrete approximation of time-to-failure distributions of the system components, the mission reliability and expected mission cost are simultaneously evaluated using the universal generating function technique. A genetic algorithm is used as an optimization tool for solving the formulated SESP problem for the 1-out-of-N: G heterogeneous cold-standby systems. Several examples are given to illustrate the considered problem and the proposed solution methodology.