The future Heterogeneous Wireless Network (HWN) is composed of multiple Radio Access Technologies (RATs) and domains, therefore, new Radio Resource Management (RRM) schemes and mechanisms are necessary to benefit from the individual characteristics of each RAT and to exploit the gain resulting from jointly considering the whole set of the available radio resources in each RAT. Vertical Handover (VHO) enables users to access several networks such as WLAN, WMAN, WPAN, and WWAN in parallel. It allows the applications even the real time application to be seamlessly transferred among different networks. In this paper, a decision support system is developed to address the VHO problem. This system combines fuzzy logic and ELECTRE, a MCDM algorithm, to the problem of VHO. This combination decreases the influence of the dissimilar, imprecise, and contradictory measurements for the VHO criteria coming from different sources. A performance analysis is done and the results are compared with traditional algorithms for VHO. These results demonstrate a significant improvement with our developed algorithm.