Abstract: The study addresses this deficiency by integrating the ‘importance-satisfaction model (I-S Model)’ and the ‘Performance Control Matrix (PCM)’ to provide a more comprehensive assessment model for improving specific quality attributes. The study applies this integrated measuring instrument in Taiwanese hot spring industry using a questionnaire survey to assess ‘importance’ and ‘satisfaction’ in their capacity as ‘internal customers’ of the industry. The study identifies quality attributes that require improvement then applies the ‘Employee Satisfaction Index (ESI)’ to determine the priority of these items for improvement. The study demonstrates that the I-S Model and the PCM, taken together, provide an excellent measuring instrument for assessing priorities for quality improvement.