A new decision‐making tool: the service performance index

Measuring service performance in an appropriate way has received widespread attention due to the vital role customer service plays in gaining competitive advantages. Since service performance directly correlates with customer satisfaction, measuring service performance that attempts to assess validity is a concern for many firms. The new proposed index, the service performance index, will involve observing the number of customer complaints that the firm receives. Since sample data must be collected to calculate these indices, the results will be exposed to sampling errors. Taking sampling errors into account, the uniformly minimum variance unbiased (UMVU) estimator is used to develop a procedure in order to generate an index value that is more reliable.