Many firms conduct satisfaction surveys of their customers, with a view to using the analyzed results to identify areas of potential improvement. The weakness in this approach is that attributes with a lower satisfaction level might not be in need of improvement. They might merely be of little concern to customers. The present research develops several methods to identify areas that do require improvement. These methods include the importance -satisfaction (I -S) model, the improvement index, the quality-improvement index, the SERVQUAL survey, Kano's model, the extent of satisfaction, and the extent of dissatisfaction. An integrated model of service-quality measurement is used to cover all the customer surveys required for an international certification service company. In the case study, valuable information of various kinds is obtained from an analysis of the customer surveys.On the basis of this information, the firm can make appropriate decisions on areas for improvement, which are significantly different from those identified on the basis of a simple satisfaction survey.