Gap analysis (GA) is one of the most popular techniques which has been widely used to help businesses make service quality improvement decisions to improve customer satisfaction. However, an assumption of linear relationship between attribute performance and customer satisfaction underlies the application of GA and was challenged while comparing with the Kano's two-dimensional model which indicated the possible phenomenon of non-linear relationship between attribute performance and customer satisfaction. Therefore, the main purpose of this research is to revise GA by redefining service quality gap and building its evaluating function through Kano's two-dimensional conception with the application of BPNN technique. To confirm the applied validity of this new GA technique, the original GA was performed to compare with the new one by an empirical study on Taiwanese HR service agency. Results showed that the impact of each service quality gap on improving customer satisfaction can be clarified by new GA technique. This implicates that new GA technique can be considered as a valuable decision-making tool for enhancing customer satisfaction more effectively.