A quality management system for products comprising: a multiplicity of barcoded quality indicators each operative to provide a machine-readable indication of exceedance of at least one threshold by one or more product quality affecting parameters, a barcode indicator reader operative to read said barcoded quality indicators and to provide output indications; and a product type responsive indication interpreter operative to receive said output indications and to provide human sensible, product quality status outputs, characterized in that each of said indicators comprises: a first barcode including at least one first colorable area, said first barcode being machine-readable before exceedance of said at least one threshold; at least a second barcode including at least one second colorable area, said second barcode not being machine-readable before exceedance of said at least one threshold; a coloring agent located at a first location on said indicator; and a coloring agent pathway operative to allow said coloring agent to move, at a rate which is at least partially a function of time, from said first location to said first and second colorable areas simultaneously for simultaneous coloring thereof upon exceedance of said threshold, thereby causing said first barcode to become unreadable and at the same time causing said second barcode to become machine-readable, each of said barcoded quality indicators being operative to provide a single machine-readable barcode readable by said barcode indicator reader, generally at all times including times prior to, during and immediately following exceedance of said at least one threshold. a multiplicity of barcoded quality indicators each operative to provide a machine-readable indication of exceedance of at least one threshold by one or more product quality affecting parameters, a barcode indicator reader operative to read said barcoded quality indicators and to provide output indications; and a product type responsive indication interpreter operative to receive said output indications and to provide human sensible, product quality status outputs, characterized in that each of said indicators comprises: a first barcode including at least one first colorable area, said first barcode being machine-readable before exceedance of said at least one threshold; at least a second barcode including at least one second colorable area, said second barcode not being machine-readable before exceedance of said at least one threshold; a coloring agent located at a first location on said indicator; and a coloring agent pathway operative to allow said coloring agent to move, at a rate which is at least partially a function of time, from said first location to said first and second colorable areas simultaneously for simultaneous coloring thereof upon exceedance of said threshold, thereby causing said first barcode to become unreadable and at the same time causing said second barcode to become machine-readable, a first barcode including at least one first colorable area, said first barcode being machine-readable before exceedance of said at least one threshold; at least a second barcode including at least one second colorable area, said second barcode not being machine-readable before exceedance of said at least one threshold; a coloring agent located at a first location on said indicator; and a coloring agent pathway operative to allow said coloring agent to move, at a rate which is at least partially a function of time, from said first location to said first and second colorable areas simultaneously for simultaneous coloring thereof upon exceedance of said threshold, thereby causing said first barcode to become unreadable and at the same time causing said second barcode to become machine-readable, each of said barcoded quality indicators being operative to provide a single machine-readable barcode readable by said barcode indicator reader, generally at all times including times prior to, during and immediately following exceedance of said at least one threshold.