Abstract This paper will develop a set of reliability worth evaluation models to evaluate the load point reliability worth indices for five different distribution types. The distribution substations, primary distribution systems, and the interaction between them contribute to the load point reliability worth indices. The reliability worth of the distribution systems are evaluated in terms of customer interruption costs, by using the sector customer damage function (SCDF). The most suitable system design is based on comparisons of the total system costs of the candidates under consideration. Four case studies are thoroughly examined in this paper. Also, the impact on customer interruption costs associated with customer type, substation configuration, and feeder configuration are investigated.