Method for generating a compatibility index between two ends of two tubes, in particular before welding operations, the method comprising the steps of: (a) marking an angular reference (M0) on each of the two ends, (b) orbital measurement of an inside radius of each of the ends; (c) determining an index of angular compatibility (INDthētak) between the two ends for an angular deviation (⊖, theta) between the angular references of the ends, said angular compatibility index deriving from a maximum difference between the inside radii of each opposite end, (d) iterating the step of determining the angular compatibility index for several values for angular deviation between the angular references of the ends; (e) generating an overall score for compatibility (Hk) between said two ends, the overall compatibility score being a function of the angular compatibility indices determined for several angular deviation values.