This work is about the analysis and optimization of radial flux modular stator synchronous machines. An outer rotor topology with surface-mounted permanent magnets is focused. The stator holds concentrated coils fixed to U-shaped segments made of laminated steel. An automated procedure for evaluating the characteristics of any design variant of this topology is presented. This includes a nonlinear finite element analysis conducted by taking advantage of a computer cluster and a consequently applied surrogate modeling technique for detailed performance evaluation. The approach is applied for solving an optimization problem with multiple objectives and several design parameters. The overall Pareto optimal results are illustrated. Selected Pareto-optimal designs are presented and compared in detail. Consequently, design guidelines can be derived that give valuable insights for future design tasks that were not yet presented in the past.