A method for corrective action on the operation of a line for the production of absorbent sanitary articles, such as nappies for babies, incontinence pads for adults or sanitary towels, each article comprising a plurality of components which are gradually positioned relative to each other and assembled along the production line; the line comprising feed means for the absorbent article and a plurality of operating stations which produce the article; associated with the line there is a system for monitoring production, for checking the quality of the articles fed out of the line and for implementing corrective action relative to any faults or defects which arose during production; the monitoring system comprising inspection means for inspecting the article for capturing at least one image of each article being fed out of the line; the inspection means comprising at least one sensor for capturing at least one image of the article and acquisition means for the image or images of the article; the monitoring system comprising a unit for processing features measured from the image by the inspection means, means for displaying information about the production line and the article, a communication network to allow circulation of the above-mentioned information; the processing unit being logically connected to the sensors with which each of the line operating stations is equipped; the acquisition means defining, using the image, first parameters indicating the positioning of at least one respective component and/or assembly and/or shape of at least one respective component; the processing unit assessing whether or not the first parameters lie within a respective acceptability range, if so, the unit identifying the presence of a production defect, the processing unit identifying the respective operating stations of the line which give the first parameters that are generating the defect; the method being characterised in that: if there is a defect in the article, the processing unit identifying second line operating parameters which are used to indicate if each first parameter is outside the respective acceptability range; the second line operating parameters indicating the operating state of a respective operating station in the line; the second line operating parameters being linked to the process for positioning, assembly and/or forming of the components of the article; the processing unit comparing the second line operating parameters with respective third reference parameters indicating optimum line operation; the second line operating parameters and the third parameters used in the comparison by the processing unit being monitored by the sensors which are mounted on each operating station; the processing unit deriving from the comparison a map of parameters indicating abnormal operation; the map representing a set of second line operating parameters which deviate from the third reference parameters, and therefore are abnormal second line operating parameters since they do not define optimum line operation and consequently result in non-optimum quality of the absorbent article; the processing unit checking if a combination of abnormal second line operating parameters of the map indicates a respective cause of line malfunction, the respective cause being included in a case record of causes of malfunction which is preset and predefined; after identifying the causes relative to the process for execution of the various operations which generated the faults on the article during production, the processing unit, based on the causes identified, generates the correction action necessary for correcting the defect. if there is a defect in the article, the processing unit identifying second line operating parameters which are used to indicate if each first parameter is outside the respective acceptability range; the second line operating parameters indicating the operating state of a respective operating station in the line; the second line operating parameters being linked to the process for positioning, assembly and/or forming of the components of the article; the processing unit comparing the second line operating parameters with respective third reference parameters indicating optimum line operation; the second line operating parameters and the third parameters used in the comparison by the processing unit being monitored by the sensors which are mounted on each operating station; the processing unit deriving from the comparison a map of parameters indicating abnormal operation; the map representing a set of second line operating parameters which deviate from the third reference parameters, and therefore are abnormal second line operating parameters since they do not define optimum line operation and consequently result in non-optimum quality of the absorbent article; the processing unit checking if a combination of abnormal second line operating parameters of the map indicates a respective cause of line malfunction, the respective cause being included in a case record of causes of malfunction which is preset and predefined; after identifying the causes relative to the process for execution of the various operations which generated the faults on the article during production, the processing unit, based on the causes identified, generates the correction action necessary for correcting the defect.