The control of the quality of a product, by selectively timing its withdrawal rate from a mixed reservoir where it is being stored, is studied. Bounds on the applicability of a feedforward strategy to achieve quality control, are evaluated by simulation and analysis of a simple case, where a periodic disturbance of known frequency is to be compensated for. Average delivery rate, reservoir capacity limits and disturbance frequency delineate the bounds on permissible control actions. Within those bounds, an optimal withdrawal strategy is demonstrated, that yields improved results, as compared to natural attenuation. It is noted, however, that this deterministic approach cannot be expected to work for uncharacterized or random disturbance.