Abstract: This study describes and uses an ant colony meta-heuristic optimization method to solve the reliability optimization problem. This problem is known as total reliability maximization of parallel-series system configuration. Redundant elements are included to achieve a high desired level of reliability. System reliability is represented by a multi-state reliability function. The systems elements are characterized by their performance (capacity), reliability and cost. These elements are chosen among a list of products available on the market. The proposed meta-heuristic seeks to the best maximal reliability system configuration with limited system investment. To estimate the parallel-series system reliability, a fast method based on Universal Moment Generating Function (UMGF) is suggested. The ant colony approach is used as an optimization technique.