In today’s competitive and interconnected supply chains, decision-making often requires collaboration among multiple decision-makers (DMs) to achieve common goals, such as selecting process technology, identifying suitable partners, adopting new technologies, and establishing operational strategies, to name few. This article addresses the challenge of selecting process technology within the context of multi-criteria group decision-making (MCGDM). The developed approach incorporates the weighted selective aggregated majority-OWA (WSAM-OWA) operator, which accounts for the varying expertise levels of DMs, significantly influencing the aggregation process. To further enhance decision accuracy, a combinative method is used to evaluate the importance of DMs and strengthen preference aggregation. The TOPSIS method is then applied to identify the most suitable alternative, using both subjective and objective weighting methods. Finally, to demonstrate the effectiveness of the proposed approach, an illustrative example dedicated to process technology selection is presented and the obtained numerical results analysed.