Multi-criteria group decision-making process using convex combination of q-rung orthopair basic probability assignment with application to medical diagnosis.

Dempster-Shafer theory (DST) and multi-criteria decision-making are widely applied mathematical tools in decision-making, though DST has some limitations in evidence fusion rule. The issues in evidence fusion are addressed through the development of combination rules, pre-processing of evidence, and generalization of evidence into interval-valued or intuitionistic belief degree. In this paper, a more flexible belief degree called the q-rung evidence set is introduced to solve the issues of standard belief degrees. Moreover, fusion of group decision-maker's belief degrees using a single fusion rule is a possible case of conflict among them. In this regard, we have employed the convex combination of two rules with different weights to generate a consensus among the decision-makers. A new aggregation method is devised to integrate the assessment of decision-maker based on the q-rung evidence set, convex combination rule, and a new score function. We have used a hypothetical case study in multi-criteria group decision-making problem for solving the patient's treatment preference problem in medical diagnosis to validate the proposed technique. The suggested technique successfully ranks the four alternatives with the comparison to the former aggregation method. [ABSTRACT FROM AUTHOR]