The impact of four reaction variables was visualized in a three-dimensional plot for three main influencing factors (equivalent, flow rate and DMAP loading), as shown in Figure . The sizes and colours of the data points represent STY and E-factor respectively, and temperature is represented using the linewidth of the points. At low equivalents, the E-factor was always low but STY was also low. When increasing the equivalent from moderate to high, more desired product was produced but at the same time more waste was generated, which resulted in a decrease of the E-factor but favored STY. Large DMAP loading accelerated the reaction and increased STY but generated more waste. The influence of temperature mainly changed the reaction rate but was not that obvious. In addition, it can be noticed that data points were quite sparse in the high equivalent from 4 to 5 compared to the low equivalent from 1 to 3, where the algorithm was more explorative in the high equivalent region.