We use the kinetic model of an automated mesoscale flow reactor system developed by Hone et al. This model simulates a multistep aromatic nucleophilic substitution reaction which produces one desired product 3 and two unwanted products 4, 5 from 2,4difluoronitrobenzene 1 and pyrrolidine 2 (Figure ). The model has four input variables and five outcome variables. The input variables consist of concentration of 2,4-difluoronitrobenzene 1 (s 1 , 0.007 -1.000 mol/l), molar equivalents of pyrrolidine 2 (s 2 , 1.0 -1.1 mol eq.), resi- The reaction has four steps, each of which has a rate constant. To model the variability in actual experiments, the rate constants are sampled from normal distributions whose mean and variance are determined in literature. Given a point in the input space, its failure rate is defined as the fraction of failure in 1,000 trials. In addition, we can evaluate additional outcomes as space time yield [kg/m 3 h],