System Installation Disparity between Theory and Practice

When the target value of functional geometrical specification is too tight, its cascade of tolerances is at the feasibility limit of production. In this case, the geometrical Tolerancing method loses its benefits and generates an excessive level of non-Conformity which induces additional costs that are not acceptable. The aim of this paper is first to introduce the background concerning chain of dimension method and tolerances capabilities based on test specimen results. Secondly, demonstrate ability to apply statistical calculation. Thirdly extend conventional chain of dimension in one dimension to multi-holes system installation. And, then analyze potential effect by stress evaluation. And confirm the demonstration of improvement on Tolerancing installation calculations, by onboarding all stakeholder (design, manufacturing, stress) early in design phase (interfaces maturation) and by analyzing more in detail installations constraints. This method should be applied first on "non-critical" junction, because it needs to be further matured and so it is not yet mature enough for primary structure and associated quality checks. In conclusion, as a result, it is possible to increase tolerance specification of parts and manage risks of non-assembly. In conclusion, tolerances for holes localization could be approximatively multiplied by two compared to basic calculation method.