The purpose of this MOAA standard is to define a set of open architecture standards, concepts & guidelines for Advanced Avionics Architectures (A3). The three main goals for the MOAA Standards are: – Reduced life cycle costs, – Improved mission performance, – Improved operational performance. The MOAA standards are organised as a set of documents including: – A set of agreed standards that describe, using a top down approach, the Architecture overview to all interfaces required to implement the core within avionics system, – The guidelines for system implementation through application of the standards. The document hierarchy is given in Figure 1: (in this figure the document is highlighted)