A method for assisting in performing tasks on a machine that forms articles from a web of material, said web of material having a length, plurality of first and second spaced apart detectable features (26, 28) on the web, and a plurality of first locations and a plurality of second locations thereon, said method comprising: a. providing a first detector for detecting one of said first detectable features on the web of material for performing a first operation at one of said first locations on the web of material at a first station; b. providing a second detector for detecting one of said second detectable features on the web of material for performing a second operation at one of said second locations on the web of material at a second station, wherein: a portion of the web of material that will form an individual article has a first location and a second location, and the steps of detecting the detectable features for the first and the second operations are carried out separately, and wherein the second operation is different from the first operation; and c. providing a compensating device that cooperates at least indirectly with the detectors for reducing any variations in position along the length of the web of material between at least one of said first locations and/or said second locations, and if necessary, moving at least a portion of the web of material to adjust the relative position of at least one of said first locations and said second locations to reduce variations therebetween; characterised in that said first and second spaced apart detectable features (26, 28) are pre-printed on the web of material and in that the second detectable features repeat on a different portion of the web of material than the first detectable features. a. providing a first detector for detecting one of said first detectable features on the web of material for performing a first operation at one of said first locations on the web of material at a first station; b. providing a second detector for detecting one of said second detectable features on the web of material for performing a second operation at one of said second locations on the web of material at a second station, wherein: a portion of the web of material that will form an individual article has a first location and a second location, and the steps of detecting the detectable features for the first and the second operations are carried out separately, and wherein the second operation is different from the first operation; and c. providing a compensating device that cooperates at least indirectly with the detectors for reducing any variations in position along the length of the web of material between at least one of said first locations and/or said second locations, and if necessary, moving at least a portion of the web of material to adjust the relative position of at least one of said first locations and said second locations to reduce variations therebetween; characterised in that said first and second spaced apart detectable features (26, 28) are pre-printed on the web of material and in that the second detectable features repeat on a different portion of the web of material than the first detectable features.