Collecting valid and efficient data is one of the primary challenges of scientific research. Quantitative or qualitative data
 usually is collected during questionnaire surveys or interviews by experts after determining the study scope and population
 number. These methods consume considerable time rounds and costs, specially faced with social constraints such as the
 Qovid 19 pandemic. Therefore, new communication technologies are necessary for faster, less costly, and more effective
 methods. This study aims to introduce the ”Focus Group” method in qualitative fuzzy-based studies. We express the history,
 instruction, and advantages of the approach. It overcomes some research limitations in multidimensional, interdisciplinary,
 and ambiguous issues. This method reduces the possibility of omitted variables in an integrated system with high speed and
 accuracy of expert opinion collection via a deep, systematic, and efficient approach using online technology. An example of
 the Focus Group method application is presented in a study of the integration of influential variables in lean and sustainable
 construction using a fuzzy DEMATEL method.