General This document is intended for use by manufacturers of aircraft@ engines and Electronic Engine Controls [EECs] as a component change process and evaluation guideline. Its purpose is to provide an effective means of managing the modification of electronic hardware. The process defined in this document is based upon: ? an understanding of the electronic component market evolution@ e.g.@ ? obsolescence; lessons learned from the effects caused by the introduction of electrical component changes in a service fleet environment; ? industry best practice; and ? an understanding of the applicable regulations. Purpose The introduction of any design change to an Electronic Engine Control system will carry a potential risk to the aircraft safety and operability. The evaluation of the impact for any change can be difficult to manage as it may require involvement of the EEC manufacturer@ the engine manufacturer and the aircraft manufacturer@ who must each support the showing of conformance to all applicable certification standards. Further complexity is brought about by the variety in the quantity and quality of the original design data. The purpose of this document is to provide guidance on how to evaluate and classify a design change. It also provides a definition of the coverage and depth of analysis necessary to manage the risk of impact on aircraft safety and operability to a satisfactory level.