In fifth generation mobile network, Radio Access Network sharing is an attractive solution for operators to counter the traffic growth and build cost-effective networks in order to improve coverage and capacity at reasonable investments and operational costs. It consists of sharing radio access resources between two or more operators. In such multi-operator environment access selection decision is an important issue for the mobile user and his home operator which the user has contract with. In literature, the majority of access selection algorithms are based on game theory which is very complex for implementation and the decision is slower in comparison with Multiple Attributes Decision Making (MADM) methods. In this paper, we use Simple Additive Weighting (SAW) methods and Nearest Performance Handover (NPH) algorithm for the access selection in a multi-operator environment. These algorithms based on MADM were initially conceived for the selection decision in a single operator environment. In addition, we compare the performance of these algorithms with our previously proposed cost function for the access selection in a multi-operator sharing network. Performance analyses are made in terms of user blocking percentages and global achieved profit. Simulation results showed that our decision algorithm guarantee the lowest blocking probability for all operators, it prevents overloading operator's with high numbers of guest users which affect own clients acceptance. In addition, it improves global achieved profits for all cooperating operators. However, SAW methods showed better performance than NPH concerning users blocking percentages, but NPH guarantees higher profits than SAW methods for the operators with limited capacity.