The most widely used models to study the quality of service are the SERVQUAL and SERVPERF models that measure service mechanisms. This paper is to estimate service efficiency and consistency for Retail Industry. We tried to measure the service quality and overall satisfaction by using DEA and PCI, degree of combination and top2box which is a little bit different methodology from traditional ones. Rather than using the usual method of converting the service quality index by mean value, the Service Efficiency Index(SEI) and Service Quality Consistency Index(SQCI) are used to measure the efficiency and consistency level, which in turn can be used as the new service quality indices. The result of SEI and SQCI show the efficiency frontier in retail industry that 6 DMUs are analyzed relative efficient DMUs, 12DMUs are inefficient DMUs and retail Industry consistency level appeared low(0.35-0.47) Also, there is a significant difference in terms of efficiency and consistency in the each retail industry. Finally, we showed the summarized result as the Effi-Con Matrix