Purpose - The purpose of this paper is to propose and empirically assess three comparative approaches to measuring service quality: Modified gap model, TOPSIS and loss function. Aims to argue for the use of TOPSIS from decision sciences, and Loss function from operations research and engineering, as alternative approaches to the gap model. Design/methodology/approach - The empirical evidence is provided by large sample consumer data on the service quality for leading Indian commercial banks. The service quality evaluations obtained from these three distinct methods are compared and tested for their mutual agreement. Findings - Fndings show that the rankings obtained from different methods are statistically in agreement, suggesting that the alternative approaches can provide equally good measurement of service quality. But they should not be used in an interchangeable manner. Research/limitations/implications - Research shows that a single measure of overall service quality based on gap model is over-simplistic. It would be more useful to explore a richer profile of customer service quality provided by different measurement approaches. Each methodology has its own advantages and disadvantages, and should be used based on its suitability for a particular application. Practical implications - This research offers profound practical implications. It offers managers with a framework of service quality improvement that measures service quality gaps, selects an optimal combination of attribute levels to deliver customer satisfaction, and focuses on reducing the future loss caused by poor quality. Originality/value - Extant marketing literature is replete with gap model applications for measuring service quality. Drawing from interdisciplinary literature, alternatives are provided to the traditional gap model, which show equally good measurement with greater suitability of application under certain conditions.