Face milling is a common procedure used in the machining of aluminium alloys. When trying to optimise the milling parameters, it is important to take into consideration the surface finish, material removal rate, tool wear, and energy consumption. The Taguchi Orthogonal Array (OA) is a well-known method of experimental design that may be utilised to optimise several parameters in a systematic manner while simultaneously keeping the number of experimental runs to a minimum. TOPSIS is a method of decision-making that involves comparing potential options to both ideal and negative ideal solutions in order to establish which one offers the most favourable outcomes for a certain issue. As a result, researchers are able to evaluate the effects of different milling parameters on the surface finish, material removal rate, tool wear, and energy consumption of aluminium during face milling by using L9 Orthogonal Array of TOPSIS optimisation. This allows them to optimise the parameters to achieve the results. © 2024 Elsevier B.V., All rights reserved.