I came across through another UXSE question the idea of customer satisfaction index used in businesses as a means to improve products and services. It seems that the gold standard is the American Customer Satisfaction Index (ACSI), and looking at their website in more detail seems to suggest that it is a combination of qualitative and quantitative measures used to create an index that can be used to compare between businesses that also use the index (much like SUS).
What was interesting about the model which the index is based on is the fact that they tried to measure perception against actual outcome, which to me is like comparing research at early stages of product concept to the user testing done at the later stages of product development. Is there a clear overlap between what the ACSI tries to achieve and the user research and testing that we do in UX?
image source: http://www.theacsi.org/about-acsi/the-science-of-customer-satisfaction