A system for conducting a retail transaction, comprising: a. a plurality of weighing assemblies in contact with a shelf and jointly operable to measure a combined weight of a shelf and of products arranged thereupon; b. one or more computer processors ; and c. a non-transient computer-readable storage medium comprising program instructions, which when executed by the one or more computer processors, cause the one or more computer processors to carry out the following steps: i. monitoring weight measurement data corresponding to the shelf and a plurality of non-homogeneous products arranged thereupon, said weight measurement data transmitted by the plurality of weighing assemblies as respective streams of weight measurement data-points; ii. responsively to a change over time in the values of said weight measurement data-points and contingent upon said values reaching respective steady states according to a stability-tracking rule, determining a set of weight-event parameters of a weight event, the determined set of weight-event parameters comprising one or more products and a product-action respective of each one of the one or more products; and iii. performing at least one of: (A) recording information about the results of the determining in a non-transient, computer-readable medium, and (B) displaying information about the results of the determining on a display device, wherein the weight measurement data-points comprise at least one type of data selected from the group comprising calculated weights and voltage inputs thereto. a. a plurality of weighing assemblies in contact with a shelf and jointly operable to measure a combined weight of a shelf and of products arranged thereupon; b. one or more computer processors ; and c. a non-transient computer-readable storage medium comprising program instructions, which when executed by the one or more computer processors, cause the one or more computer processors to carry out the following steps: i. monitoring weight measurement data corresponding to the shelf and a plurality of non-homogeneous products arranged thereupon, said weight measurement data transmitted by the plurality of weighing assemblies as respective streams of weight measurement data-points; ii. responsively to a change over time in the values of said weight measurement data-points and contingent upon said values reaching respective steady states according to a stability-tracking rule, determining a set of weight-event parameters of a weight event, the determined set of weight-event parameters comprising one or more products and a product-action respective of each one of the one or more products; and iii. performing at least one of: (A) recording information about the results of the determining in a non-transient, computer-readable medium, and (B) displaying information about the results of the determining on a display device, i. monitoring weight measurement data corresponding to the shelf and a plurality of non-homogeneous products arranged thereupon, said weight measurement data transmitted by the plurality of weighing assemblies as respective streams of weight measurement data-points; ii. responsively to a change over time in the values of said weight measurement data-points and contingent upon said values reaching respective steady states according to a stability-tracking rule, determining a set of weight-event parameters of a weight event, the determined set of weight-event parameters comprising one or more products and a product-action respective of each one of the one or more products; and iii. performing at least one of: (A) recording information about the results of the determining in a non-transient, computer-readable medium, and (B) displaying information about the results of the determining on a display device, <EOS>