Reliability analysis of distribution systems has been attracting increasing attention. A special concern pertains to the distribution networks on which most failures occurs. The optimization of distribution system of breakers and power switches is a possible strategy to improve reliability. The paper describes development procedure for modelling restoring after a fault and calculating associated reliability indices and customers’ outage costs. The developed model of the network and reliability and outage costs calculating algorithm is suitable for multi-criteria analysis of the network. Proposed reliability and outage costs calculation algorithm is based on Monte Carlo simulation and genetic algorithm.