This paper introduces a methodology to solve opened issues associated to “on field” large repair of primary principal structures for composites. If a repair is mandatory, it leads to a costly immobilization. Structural damage needs a “case by case” solution including design, calculation phases, damaged zone removal, patch construction, set-up and finishing. Furthermore composite solution needs to be considered with its real “industrial” variabilities and with a continuous link between all scales (from micro scale to structure scale). To address such challenges, Multi-Instrumented Technological Evaluators (MITEs) Toolbox is developed in order to restitute the representative working conditions of repair areas in industrial structures. Thanks to multi-axial modular test device, multi-axial loadings are chosen for placing the repair zone under a chosen representative strain fields. Results are discussed through comparison between experimental data and FE models results for several Multi-Instrumented Technological Evaluator types.