A description is given of an installation which makes it Possible to manage the cutting into Plates of float glass emerging from the annealing tunnel of a production unit, taking account of the pre-established quality criteria and the requirements imposed by the order book. This unit comprises first of all a device for detecting volume defects, based on scanning of the strip by a laser beam, which makes it possible to obtain, in real time, an electronic image of a section of the strip, showing the position and dimensions of the various defects. Secondly, this image is used in a data processing device which allocates to it an optimisation algorithm which Provides an optimal cutting diagram taking account of all the quality characteristics and the reauirements of orders. All the onerations are carried out fairly quickly, so that the cutting un can be controlled by the computer which, by another route, also controls sending of the cut sheets to the various packing stations, each corresponding to a different customer. Finally, this same computer checks the actual packaging of the cut sheets of glass.