With the huge global and wide range of attention placed upon quality, promoting and optimize the reliability of the products during the design process has turned out to be a high priority. In this study, the researcher have adopted one of the existing models in the reliability science and propose a bi-objective model for redundancy allocation in the series-parallel systems in accordance with the redundancy policy- given that failure rate depends on the number of the active elements. The objective behind the proposed model is to maximize the reliability and to minimize the total cost of the system. Internal connection cost, which is the most common parameter in electronic systems, put in this model in order to simulate the real-world conditions. As the proposed model is an NP-Hard one(for getting results), the researcher adopted a Non-dominated Sorting Genetic Algorithm (NSGA II) after optimizing its operatorsâ€™ rate by using Response Surface Methodology (RSM).