Application of model-based diagnostic technology on the Boeing 777 Airplane

This paper describes the application of model based diagnostic technology to the Central Maintenance Computer for the Boeing 777 Airplane. The paper presents an overview of model based diagnostic technology as applied to the 777 with an emphasis on the model generation process. It identifies the subtleties of developing a model with the appropriate level of resolution. A model that is too general will not provide the required accuracy while a model that is too detailed will be burdensome to develop and maintain. The fact that data entry activities for parts of the model needed to start before the model was completely specified was the source of additional difficulties that the process had to overcome. The paper presents how these problems were solved on the 777 and how this experience can be beneficial in future programs