A Demerit Control Chart for Customer Satisfaction Survey

Purpose: The main purpose of this article is to present the advances of control chart techniques in nonmanufacturing processes. Specifically, we present a new approach to monitor service quality with time. This study uses the performance of the demerit control chart to monitor the negative responses or nonconformities with respect to the service quality characteristic. These charts assign the different weight to each negative responses, regard of the degree of unfavorable. Design/methodology/approach: Applying of the demerit control chart to monitor the customer survey data is discussed. The procedure of constructing the proposed chart is described by a numerical example using data collected in an assessment of library service quality at a private university in Thailand. Findings: The control chart shows one sample that is above the upper control limit this could indicate that an assignable cause affected those quality characteristic. Perhaps those service offered might less than student expectation. Action should be taken to figure out how to address the issues in those items and bring the process back to the in-control condition. Applying of SPC is helpful to promote service quality. Originality/value: In this study, we mention that the method to analyze the nonconforming of survey results by combine the negative responses as "nonconforming" are not applicable. This paper explores new technique in service quality research and the results show that such approach can provide more realistic to monitoring a count of different categories of negative responses.