The simulated moving-bed process (SMB) is used for continuous chromatographic separation in chemical engineering and biotechnology. In the usual operating scheme of SMB processes, the operating parameters, namely, the fluid volume flows, are kept constant. In this contribution, a new way of operating the process with volume flows varied within each switching interval is suggested. It is shown that the solvent consumption can be reduced substantially for a given feed throughput. Alternatively, the purity can be increased while keeping both the solvent consumption and the throughput constant.