With more than 27% of the final heat demand in Europe consumed by the industrial sector, solar heat for the industrial process is one of the hottest topics nowadays, leading to many initiatives to make pilot projects in central and southern Europe. This paper analysed two analytical methods to optimise the essential working parameters (solar collectors, glycol ratio, volume flow rate, relative tank capacity, and tank height/diameter ratio) in a pasteurising plant located in Budapest, Hungary. The first method is an analytical approach to determine the optimum values considering the other variables at fixed levels. In contrast, the other one is linear modelling using response surface method RSM and R script coding program to identify the most influential factors using Pareto plots and then discussing the most important two factors' interactions. This research aims to identify which method is better for optimising solar heat for industrial (SHIP) systems. The paper compares the previously mentioned methods, and the results are compared with the results from the other authors. As a result, all factors showed similar magnitudes in both methods except for relative flow rate which was neutral in the analytical method and positive in the RSM.