The offshore/onsite teams' effectiveness of knowledge transfer is significantly measured by a various kinds of factors. In this paper, we propose a Knowledge Transfer (KT) assessment framework which is integrates four criterions: knowledge, team, technology, and organization factors to evaluate KT effectiveness of GSD teams. In this context, we presents fuzzy DEMATEL approach for assessing GSD teams KT effectiveness based on intuitionistic fuzzy numbers (IFNs). In this approach, decision makers provided their subjective judgments on the criteria, characterized on the basis of intuitionistic fuzzy sets. Moreover, intuitionistic fuzzy sets are used in the fuzzy DEMATEL approach can be effectively assessing the KT effectiveness criteria, rank the alternatives. Subsequently, the complete process is illustrated with GSD teams' KT evaluation criteria samples, the factors are ranked using fuzzy linguistic variables which are mapped to IFNs. In that case, IFNs has been converted into their corresponding basic probability assignments (BPAs) and then Dempster-Shafer theory is used to combine the group decision making process. Besides, illustrate applicability and usefulness of proposed approach in group decision making process for evaluation of multiple criteria's under fuzzy environment has been tested by software professionals at Inowits software organization in India.