Airbus business and Extended Enterprise require more and more involvement of design and built suppliers, tier 1 but also across the complete supply chain i.e. tier 2-n. These suppliers are not working only for Aerospace industry and may have different cultures. The pressure on cost and overall efficiency is high and everybody has to cope with obsolescence and new regulation (e.g. REACH (Registration, Evaluation and Authorization and Restriction of Chemicals)). So it became very important for Airbus to clarify the criteria under which a change can be done without Airbus review, and criteria under which a change can be done without Airworthiness authority review.This document details the Airbus recommendations and requirements to ensure full compliance with Part 21 to Airbus (and suppliers) with regards to: Change to Aircraft Type DesignChange to Aircraft Type Design identificationChange to Aircraft Type Design identification assessmentThis covers the complete scope of the detail design of the Aircraft. As the management of the Aircraft documentation is different depending of the domain, we have split the presentation in 3 sections: Structure, System & Cabin installationEquipmentPropulsion system.