Method, devices and program for computer-aided analysis of the failure tolerance of an aircraft system, using critical event charts

1. A method for a computer-aided preparation of a failure tolerance report for a system of an aircraft comprising a plurality of subsystems, at least one subsystem of said plurality of subsystems having a computer processor and performing monitoring and notification of at least one detected event, the method comprising:

implementing, via the computer processor, a critical event chart at least partially modelling said system, said critical event chart comprising a plurality of nodes, each node of said plurality of nodes being linked by a logical implication relation to at least one other node of said plurality of nodes, said plurality of nodes comprising:

a plurality of nodes each representing a notification message capable of being received;

at least one node representing a critical event; and,

a plurality of nodes each representing an element of said system, which is liable to failure, and each such element comprising a suspect candidate item;

receiving, via the computer processor, at least one message notifying the occurrence of said at least one detected event, said detected event comprising said at least one node representing said critical event;

creating, via the computer processor, a minimal diagnostic set relative to said at least one detected event, comprising a plurality of said elements suspected of resulting in said at least one detected event, each element of said minimal diagnostic set being represented by a node of said critical event chart and determined according to at least one logical implication relation of said critical event chart with said node representing said critical event associated with said at least one received notification message;

selecting, via the computer processor, at least one receivable notification message represented by said node of said critical event chart;

identifying, via the computer processor, elements of said minimal diagnostic set capable of resulting in the generation of said at least one selected notification message, said identified elements forming part of said failure tolerance report; and

calculating a remaining distance before an imminent effect for at least one of said identified elements, said remaining distance being calculated as being equal to a number of the elements that do not form part of said minimal diagnostic set as said suspect candidate item, a malfunction of which being necessary for the generation of said at least one selected notification message.

2. The method according to claim 1 , wherein said step of identifying elements comprises a step of extracting at least one subchart from said critical event chart, said at least one subchart comprising at least one node representing at least one message which can be generated by the malfunction of an element of said minimal diagnostic set.

3. The method according to claim 2 , further comprising a step of comparing said at least one message associated with said at least one node of said at least one subchart with said at least one selected notification message.

4. The method according to claim 3 , further comprising a step of creating a second minimal diagnostic set on the basis of said at least one subchart, in response to said comparison step, said minimal diagnostic set being called a first minimal diagnostic set, and a step of selecting minimal diagnostics on the basis of said second minimal diagnostic set, said identified elements originating from said selection of minimal diagnostics.

5. The method according to claim 1 , further comprising a step of obtaining and assigning attributes to said identified elements.

6. The method according to claim 1 , further comprising a step of generating said failure tolerance report.

7. The method according to claim 1 , further comprising a step of selecting at least one failure resolution procedure involving at least one of said identified elements.

8. The method according to claim 1 , according to which said critical event chart is at least partially generated by instantiation of at least one generic subchart.

9. A non-transitory computer-readable medium storing instructions executable by a computer processor to perform a computer-aided preparation of a failure tolerance report for a system of an aircraft comprising a plurality of subsystems, at least one subsystem of said plurality of subsystems configured for monitoring and notification of at least one detected event, comprising instructions to:

implement, via the computer processor, a critical event chart at least partially modelling said system, said critical event chart comprising a plurality of nodes, each node of said plurality of nodes being linked by a logical implication relation to at least one other node of said plurality of nodes, said plurality of nodes comprising:

a plurality of nodes each representing a notification message capable of being received;

at least one node representing a critical event; and,

a plurality of nodes each representing an element of said system, which is liable to failure, and each such element comprising a suspect candidate item;

receive, via the computer processor, at least one message notifying the occurrence of said at least one detected event, said detected event comprising said at least one node representing said critical event;

create, via the computer processor, a minimal diagnostic set relative to said at least one detected event, comprising a plurality of said elements suspected of resulting in said at least one detected event, each element of said minimal diagnostic set being represented by a node of said critical event chart and determined according to at least one logical implication relation of said critical event chart with said node representing said critical event associated with said at least one received notification message;

select, via the computer processor, at least one receivable notification message represented by said node of said critical event chart;

identify, via the computer processor, elements of said minimal diagnostic set capable of resulting in the generation of said at least one selected notification message, said identified elements forming part of said failure tolerance report; and

calculate a remaining distance before an imminent effect for at least one of said identified elements, said remaining distance being calculated as being equal to a number of the elements that do not form part of said minimal diagnostic set as said suspect candidate item, a malfunction of which being necessary for the generation of said at least one selected notification message.

10. An aircraft maintenance system comprising a calculator having a computer processor configured for performing each of the following instructions, the system comprising instructions to:

implement, via the computer processor, a critical event chart at least partially modelling said system, said critical event chart comprising a plurality of nodes, each node of said plurality of nodes being linked by a logical implication relation to at least one other node of said plurality of nodes, said plurality of nodes comprising:

a plurality of nodes each representing a notification message capable of being received;

at least one node representing a critical event; and,

a plurality of nodes each representing an element of said system, which is liable to failure, and each such element comprising a suspect candidate item;

receive, via the computer processor, at least one message notifying the occurrence of said at least one detected event, said detected event comprising said at least one node representing said critical event;

create, via the computer processor, a minimal diagnostic set relative to said at least one detected event, comprising a plurality of said elements suspected of resulting in said at least one detected event, each element of said minimal diagnostic set being represented by a node of said critical event chart and determined according to at least one logical implication relation of said critical event chart with said node representing said critical event associated with said at least one received notification message;

select, via the computer processor, at least one receivable notification message represented by said node of said critical event chart;

identify, via the computer processor, elements of said minimal diagnostic set capable of resulting in the generation of said at least one selected notification message, said identified elements forming part of said failure tolerance report; and

calculate a remaining distance before an imminent effect for at least one of said identified elements, said remaining distance being calculated as being equal to a number of the elements that do not form part of said minimal diagnostic set as said suspect candidate item, a malfunction of which being necessary for the generation of said at least one selected notification message.

11. The method according to claim 1 , further comprising identifying and selecting a troubleshooting procedure being common to at least two elements of said system, said at least two elements being represented as liable to the failure, for a resolution of diagnostic problems for resolving at least one diagnostic problem.