Purpose: This document is intended as a top-level design guide for Integrated Modular Avionics (IMA) which replace ARINC 700-series avionics. It provides guidance for the design and implementation of avionics equipment for airplanes designed after 1990. It represents the consensus of airline representatives, airframe manufacturers and avionics equipment designers. The document is conceptual in nature and covers broad subjects of operational objectives, fault tolerance, hardware components, software design and certification issues. In covering all these issues, the document attempts to be as inclusive as possible, while being general enough to be applicable to new and developing technologies. It includes design philosophy and recommended practices concerning the design of IMA, and as such, is expected to establish a starting point for the actual implementation by avionics manufacturers.