Method and device for finding spurious maintenance messages

Claim 1

A method for determining whether a maintenance message generated, during an operating cycle of a system, by a maintenance device monitoring said system, is representative of a real fault in said system or whether this maintenance message is spurious, wherein, at the end of said operating cycle, the method comprising the steps of: (a) determining a long-term occurrence rate of said maintenance message, on the basis of the results of a number N of preceding cycles, the occurrence rate corresponding to the average probability of occurrence, that is, to say of generation, of said maintenance message in the course of a cycle, said long-term occurrence rate being equal to the ratio between the number of occurrences of said maintenance message during the N cycles considered and the number of N cycles; (b) determining a short-term occurrence rate of said maintenance message, at the most on the basis of the results of the last N cycles, and wherein said short-term occurrence rate Tc is calculated on the basis of the relation: ##EQU7## in which k represents the number of occurrences of the maintenance message during the last N cycles and Pn is defined on the basis of df(n) which represents, for an occurrence n, the number of cycles since the preceding occurrence n-1; (c) comparing said short-term occurrence rate with said long-term occurrence rate; and (d) deducing therefrom: (i) if the short-term occurrence rate is higher than the long-term occurrence rate, that said maintenance message is representative of a real fault in the system; and (ii) otherwise, that said maintenance message is spurious.

Claim 2

A method for determining whether a maintenance message generated, during an operating cycle of a system, by a maintenance device monitoring said system, is representative of a real fault in said system or whether this maintenance message is spurious, wherein, at the end of said operating cycle, the method comprising the steps of: (a) determining a long-term occurrence rate of said maintenance message, on the basis of the results of a number N of preceding cycles, the occurrence rate corresponding to the average probability of occurrence, that is, to say of generation, of said maintenance message in the course of a cycle, said long-term occurrence rate being equal to the ratio between the number of occurrences of said maintenance message during the N cycles considered and the number of N cycles; (b) determining a short-term occurrence rate of said maintenance message, at the most on the basis of the results of the last N cycles, and wherein said short-term occurrence rate Tc is calculated on the basis of the relation: ##EQU7## in which k represents the number of occurrences of the maintenance message during the last N cycles and Pn is defined on the basis of df(n) which represents, for an occurrence n, the number of cycles since the preceding occurrence n-1; (c) comparing said short-term occurrence rate with said long-term occurrence rate; and (d) deducing therefrom: (i) if the short-term occurrence rate is higher than the long-term occurrence rate, that said maintenance message is representative of a real fault in the system; and (ii) otherwise, that said maintenance message is spurious.

Claim 4

A method for determining whether a maintenance message generated, during an operating cycle of a system, by a maintenance device monitoring said system, is representative of a real fault in said system or whether this maintenance message is spurious, wherein, at the end of said operating cycle, the method comprising the steps of: (a) determining a long-term occurrence rate of said maintenance message, on the basis of the results of a number N of preceding cycles, the occurrence rate corresponding to the average probability of occurrence, that is, to say of generation, of said maintenance message in the course of a cycle, said long-term occurrence rate being a dependent function of the number k of occurrences of said maintenance message during the N cycles observed, said long-term occurrence rate T1 being defined by the relation: ##EQU9## in which a5, a6 and a7 represent constants, and wherein fe(k) represents the number of cycles necessary to obtain k occurrences; (b) determining a short-term occurrence rate of said maintenance message at the most on the basis of the results of the last N cycles; (c) comparing said short-term occurrence rate with said long-term occurrence rate; and (d) deducing therefrom: (i) if the short term occurrence rate is higher than the long-term occurrence rate, that said maintenance message is representative of a real fault in the system; and (ii) otherwise, that said maintenance message is spurious.

Claim 5

A method for determining whether a maintenance message generated, during an operating cycle of a system, by a maintenance device monitoring said system, is representative of a real fault in said system or whether this maintenance message is spurious, wherein, at the end of said operating cycle, the method comprising the steps of: (a) determining a long-term occurrence rate of said maintenance message, on the basis of the results of a number N of preceding cycles, the occurrence rate corresponding to the average probability of occurrence, that is, to say of generation, of said maintenance message in the course of a cycle, said long-term occurrence rate being a dependent function of the number k of occurrences of said maintenance message during the N cycles observed, said long-term occurrence rate T1 being defined by the relation: ##EQU9## in which a5, a6 and a7 represent constants, and wherein fe(k) represents the number of cycles necessary to obtain k occurrences; (b) determining a short-term occurrence rate of said maintenance message at the most on the basis of the results of the last N cycles; (c) comparing said short-term occurrence rate with said long-term occurrence rate; and (d) deducing therefrom: (i) if the short term occurrence rate is higher than the long-term occurrence rate, that said maintenance message is representative of a real fault in the system; and (ii) otherwise, that said maintenance message is spurious.