Modest, ChristianChristianModestThielecke, FrankFrankThielecke2020-04-292020-04-292016-06-01CEAS Aeronautical Journal 2 (7): 315-331 (2016-06-01)http://hdl.handle.net/11420/5961Modern aircraft systems comprise hardware and software with high complexity. In order to assure an operation at high availability and low maintenance cost, diagnosis functions become essential. These functions detect faults and failures, identify sources of faults and failures and assess the current state of health. A reduction in operating cost, better planning of maintenance actions, and new business cases for operator and equipment manufactures are gained as a result. A systematic approach for the design and test of diagnosis functions supported by an integrated model-based tool chain is introduced in this paper. That is the SPYDER concept, a Software Package for sYstem Diagnosis EngineeRing. Embedded into the general system development process, a stepwise design and test of diagnosis functions is performed. It focuses on failures and starts with failure–effect analysis, continues with sensor placement and proceeds further to configuration and testing. The method has been applied to multifunctional fuel cell systems that are used as illustrative examples.en1869-559020162315331Expert systemsFailure diagnosisFuel cellsModel-based systems engineeringJournal Article10.1007/s13272-016-0189-0Other