1. A barcoded quality indicator operative to provide a machine-readable indication of exceedance of at least one threshold by at least one product quality affecting parameter, said barcoded quality indicator being readable by a barcode indicator reader at all times, after first becoming readable, including times prior to, during and immediately following exceedance of said at least one threshold by said at least one product quality affecting parameter, said barcoded quality indicator providing a first machine-readable indication prior to said exceedance of said at least one threshold and a second machine-readable indication, different from said first machine-readable indication, following said exceedance of said at least one threshold, said barcoded quality indicator comprising: a barcode comprising black areas and transparent areas arranged along a barcode axis; at least one colorable element at least partially underlying said transparent areas; and at least one coloring agent adapted to color said at least one colorable element in response to exceedance of said at least one threshold, said at least one coloring agent passing along a pathway to said at least one colorable element in a time corresponding to said threshold, said pathway being configured such that said coloring agent progressively colors said colorable element in a direction generally perpendicular with respect to said barcode axis, thereby enabling said barcode to be readable while said colorable element is being progressively colored.
1. A barcoded quality indicator operative to provide a machine-readable indication of exceedance of at least one threshold by at least one product quality affecting parameter, said barcoded quality indicator being readable by a barcode indicator reader at all times, after first becoming readable, including times prior to, during and immediately following exceedance of said at least one threshold by said at least one product quality affecting parameter, said barcoded quality indicator providing a first machine-readable indication prior to said exceedance of said at least one threshold and a second machine-readable indication, different from said first machine-readable indication, following said exceedance of said at least one threshold, said barcoded quality indicator comprising: a barcode comprising black areas and transparent areas arranged along a barcode axis; at least one colorable element at least partially underlying said transparent areas; and at least one coloring agent adapted to color said at least one colorable element in response to exceedance of said at least one threshold, said at least one coloring agent passing along a pathway to said at least one colorable element in a time corresponding to said threshold, said pathway being configured such that said coloring agent progressively colors said colorable element in a direction generally perpendicular with respect to said barcode axis, thereby enabling said barcode to be readable while said colorable element is being progressively colored. 5. A quality management system according to claim 1 and wherein during exceedance of said threshold said coloring agent colors part of said colorable element such that said first machine-readable indication is provided by portions of said transparent areas lying above areas of said colorable element not colored by said coloring agent read together with areas of said barcode not lying above said colorable element, and said second machine-readable indication is provided by portions of said transparent areas lying above areas of said colorable element colored by said coloring agent read together with areas of said barcode not lying above said colorable element.