Two different strategies presented determine the sets of operating conditions that yield desired product purities for an SMB separator. The search was performed numerically by solving the analogous true-moving-bed model equations. A linear equilibrium binary mixture and mass-transfer effects were taken into account by using a bilinear driving force approximation to describe intraparticle diffusion. The strategies are equivalent and produce the same results. Comparison with the linear equilibrium model strategy indicates that there are new limiting values for the flow-rate constraints in the presence of mass-transfer effects. The constraints on sections I, II and III were more restrictive than those derived from equilibrium models, whereas the constraint on section IV was less affected. Qualitative observations drawn from a model of intermediate complexity were also presented to confirm our results.