This paper investigates the influence of critical process parameters on the centrifugal casting of A356 (Al-Si) alloys using a casting simulation tool. Effects of mould rotation, pouring temperature, mould aspect ratio, and heat transfer coefficient on filling and solidification behaviours have been studied. Furthermore, the study employs Grey Relation Analysis, Taguchi, and ANOVA to systematically optimize the casting process parameters, addressing uncertainties and identifying statistically significant factors. Process optimization, supported by numerical simulations, has revealed that the optimal configuration (rotation of 150 rpm, aspect ratio as 2, pouring temperature as 775°C) minimizes stress and strain (maximum shear stress, average normal stress, principal stress, principal strain) that can be considered to be responsible for the occurrence of defects such as cracks in final castings. Controlling these process parameters will help in reducing overall stresses and in turn reducing defects as well as improvement of overall productivity.