An inspection system adapted to perform retro positive material identification of components of a multi-feature system. The layout data is fractionated to create control data for a pattern generator. A bodyside liner between the absorbent body and the skin of the wearer stretches, but to a lesser extent than the absorbent body and the outer cover. In the invention, the measurements are used to select a geometric model which comprises, at the most, quadratic surfaces, the selected geometric model is simplified to reduce the number of quadratic surfaces, the measurement results are inserted in the simplified geometric model, and the position of the device is determined by solving the simplified geometric model.