Nordic model is based on disconfirmation
paradigm by comparing perceived performance and expected service. This was the first attempt to
measure quality of service. Gronroos model was general and without offering any technique on
measuring technical and functional quality. Rust & Oliver (1994) tried to refine the Nordic model by The
Three-Component Model. They suggest three components: service product (i.e., technical quality),
service delivery (i.e., functional quality), and service environment but they did not test their model and
just a few support have been found.