Dear Colleagues;

I need some help for my research project. I want to use fuzzy weighted SERVQUAL scale to get VOC information at my QFD project. But I mixed up in assigning importance level method... In some studies researchers use SERVQUAL expectation scores for importance level, in some studies they use the GAP score (expectation-perception)... But as I read it is recommended to apply Chang's fuzzy extended analytical hierarchy to determine the importance level of customer needs at fuzzy QFD projects. I couldn't find any study that uses Chang's fuzzy extended AHP to assign importance level at QFD projects which use SERVQUAL scale to gather voice of customer. Which method would be best for importance level? SERVQUAL expectation scores or GAP scores or fuzzy extended analytical hierarchy?