Abstract: A method and system for conflict detection during construction of complex databases, such as a data model for driving or modeling a complex system. Components of a data model may be defined in rules that specify objects of various types and containing various elements. The rules are declarative, and may be stored on a computer-readable storage medium. Rule declarations or assertions include element definitions, values or ranges of values, inclusion requirements, and severity level conditions in the event that conflicts or errors are detected. Conflict checking takes account of compliance with type definitions, as well as a user identity and a phase of construction of the data model.

Abstract: A relational database is for relating maintenance information that differs for each of a plurality of complex systems, such as a plurality of differing aircraft, using a common database structure so as to facilitate maintenance procedures for the plurality of complex systems. The database structure comprises: a plurality of primary entities for providing a fault model description of each of the plurality of complex systems, the fault model description including, for each of the plurality of complex systems, failure modes, symptoms and data required to effect a repair; and a categorical entity corresponding to a complex system, such as an aircraft, that enables selection of the fault model description corresponding to the complex system or aircraft. The relational database is particularly suited for use in or by an aircraft maintenance and diagnostic system that assists with fault correction for a fault condition within an aircraft based on a fault model for the aircraft.

Abstract: A method for improving fault isolation for failure modes in complex systems, and a software program embodying the method or a corresponding method together with a computer based aircraft diagnostic system using such software is described. The method includes: capturing a set of symptoms that is consistent with a failure mode of the complex system; identifying a set of repairs for the complex system that are consistent with the set of symptoms; ranking, when the set of repairs includes more than one repair, the repairs in a sequence that will minimize an average cost to repair the complex system, the sequence including a historical component and reflecting the effectiveness of available test results to resolve each the repairs; determining possible tests that are consistent with the failure mode; and ranking the possible tests according to there respective net improvement in the average cost to repair the complex system.

Abstract: A relational database is for relating maintenance information that differs for each of a plurality of complex systems, such as a plurality of differing aircraft, using a common database structure so as to facilitate maintenance procedures for the plurality of complex systems. The database structure comprises: a plurality of primary entities for providing a fault model description of each of the plurality of complex systems, the fault model description including, for each of the plurality of complex systems, failure modes, symptoms and data required to effect a repair; and a categorical entity corresponding to a complex system, such as an aircraft, that enables selection of the fault model description corresponding to the complex system or aircraft. The relational database is particularly suited for use in or by an aircraft maintenance and diagnostic system that assists with fault correction for a fault condition within an aircraft based on a fault model for the aircraft.

Abstract: A method for improving fault isolation for failure modes in complex systems, and a software program embodying the method or a corresponding method together with a computer based aircraft diagnostic system using such software is described.

Abstract: A method for improving fault classifications for failure modes in complex systems, and a software program embodying the method or a corresponding method together with a computer based aircraft diagnostic system using such software is described. The method includes: capturing an observation that is consistent with a discrepancy of the complex system; identifying a set of failure modes of the complex system that are consistent with the observation; ranking, when the set includes more than one failure mode, the failure modes according to a degree of support the observation provides for each failure mode, the degree of support including a historical component; determining additional possible observations that are consistent with any failure mode included in the set; and ranking the possible observations according to how rapidly they reduce a number of failure modes included in the set; then preferably selecting a further observation and repeating the above steps until only one failure mode remains.

Abstract: A method for improving fault classifications for failure modes in complex systems, and a software program embodying the method or a corresponding method together with a computer based aircraft diagnostic system using such software is described. The method includes: capturing an observation that is consistent with a discrepancy of the complex system; identifying a set of failure modes of the complex system that are consistent with the observation; ranking, when the set includes more than one failure mode, the failure modes according to a degree of support the observation provides for each failure mode, the degree of support including a historical component; determining additional possible observations that are consistent with any failure mode included in the set; and ranking the possible observations according to how rapidly they reduce a number of failure modes included in the set; then preferably selecting a further observation and repeating the above steps until only one failure mode remains.