A method of producing on an apparatus a plurality of product packages that include a pouch by adjusting on an ongoing basis a fill rate at which the product is filled and a corresponding product volume contained within the pouch, the method comprising: while operating the apparatus in one of a plurality of index levels, forming, filling, and sealing the product packages using initial values for the fill rate and the volume, each of the index levels representing a tolerance range; measuring a weight of the product packages as they are produced by the apparatus; in a first feedback control loop: calculating, based on the measured weights, a first adjusted measure of the fill rate and a first adjusted measure of the volume; comparing the first adjusted measure of volume against a plurality of first tolerance ranges, each first tolerance range corresponding to one of the plurality of index levels, the first tolerance ranges comprising a widest first tolerance range at a first index level and a narrowest first tolerance range at a second index level; and in a second feedback control loop: calculating, based on the measured weights, a second adjusted measure of the fill rate and a second adjusted measure of the volume; comparing the measured weight against a plurality of second tolerance ranges, each second tolerance range corresponding to one of the plurality of index levels, the second tolerance ranges comprising a widest second tolerance range at the first index level and a narrowest second tolerance range at the second index level; wherein if the first adjusted measure of volume is within a first tolerance range corresponding to a current index level, adjusting the apparatus using the first adjusted measure of the fill rate and the first adjusted measure of the volume and changing the index level in a direction from the first index level towards the second index level, and wherein if the measured weight is outside of a current second tolerance range corresponding to the current index level, adjusting the apparatus using the second adjusted measure of the fill rate and the second adjusted measure of the volume and changing the index level in a direction from the second index level towards the first index level. while operating the apparatus in one of a plurality of index levels, forming, filling, and sealing the product packages using initial values for the fill rate and the volume, each of the index levels representing a tolerance range; measuring a weight of the product packages as they are produced by the apparatus; in a first feedback control loop: calculating, based on the measured weights, a first adjusted measure of the fill rate and a first adjusted measure of the volume; comparing the first adjusted measure of volume against a plurality of first tolerance ranges, each first tolerance range corresponding to one of the plurality of index levels, the first tolerance ranges comprising a widest first tolerance range at a first index level and a narrowest first tolerance range at a second index level; and calculating, based on the measured weights, a first adjusted measure of the fill rate and a first adjusted measure of the volume; comparing the first adjusted measure of volume against a plurality of first tolerance ranges, each first tolerance range corresponding to one of the plurality of index levels, the first tolerance ranges comprising a widest first tolerance range at a first index level and a narrowest first tolerance range at a second index level; and in a second feedback control loop: calculating, based on the measured weights, a second adjusted measure of the fill rate and a second adjusted measure of the volume; comparing the measured weight against a plurality of second tolerance ranges, each second tolerance range corresponding to one of the plurality of index levels, the second tolerance ranges comprising a widest second tolerance range at the first index level and a narrowest second tolerance range at the second index level; calculating, based on the measured weights, a second adjusted measure of the fill rate and a second adjusted measure of the volume; comparing the measured weight against a plurality of second tolerance ranges, each second tolerance range corresponding to one of the plurality of index levels, the second tolerance ranges comprising a widest second tolerance range at the first index level and a narrowest second tolerance range at the second index level; wherein if the first adjusted measure of volume is within a first tolerance range corresponding to a current index level, adjusting the apparatus using the first adjusted measure of the fill rate and the first adjusted measure of the volume and changing the index level in a direction from the first index level towards the second index level, and wherein if the measured weight is outside of a current second tolerance range corresponding to the current index level, adjusting the apparatus using the second adjusted measure of the fill rate and the second adjusted measure of the volume and changing the index level in a direction from the second index level towards the first index level.