Selection of suitable weapon for armed forces is one of the most complex decisions, which must be taken by martial administrators. The procedure of decision making on weapon selection is integrated with various criteria, which are often in conflict. This paper presents a multi criteria decision making problem based on the implementation of ELECTRE III technique. The proposed model compares all acceptable choices based on a systematic and sophisticated procedure and provides some efficient solutions. The implementation of the proposed model is demonstrated for an infantry rifle selection. The proposed model, first, determines acceptable choices and criteria through Simos method and then it uses ELECTRE III to rank various alternatives. The result of the application of the proposed model for a real-world case study of choosing an infantry rifle indicates its effectiveness.

Decision making problem is the process of finding the best option out of all feasible alternatives. There are some methods for solving Multiple Criteria Decision-Making problems and Simple Additive Weighting (SAW) is one of the most popular ones. In this paper, among multi-criteria models in making complex decisions and multiple attribute models for the most preferable choice, SAW technique is extended using interval numbers. For this purpose, we first propose a method for extending Entropy method for dealing with interval data, and then the extended SAW method with interval data is proposed by using the interval weights derived by the proposed interval Entropy method. The extended SAW method is an algorithm to determine the most preferable choice out of all possible choices, when the input data are stated in interval.