Prioritized test procedure and step display using statistical feedback

• US 7,142,960 B2
• Filed: 10/14/2004
• Issued: 11/28/2006
• Est. Priority Date: 10/14/2004
• Status: Active Grant

• Current Assignee: Snap-On Incorporated
• Original Assignee: Snap-On Incorporated
• Inventors: Grier, Jeff, Trsar, Dale A., Cancilla, James J., Reddy, Sunil P., Lewis, Bradley R.
• Primary Examiner(s): Tran, Dalena
• Application Number:
  US10/966,578
• Publication Number:
  US 20060085108A1
• Time in Patent Office: 775 Days
• Field of Search: 701/29, 701/99, 701/30, 701/36, 701/34, 701/35, 701/100, 701/107, 702/108, 702/113, 714/1, 714/25, 714/37, 714/41
• US Class Current: 701/29
• CPC Class Codes: G05B 2219/24053 Diagnostic of controlled machine
• CPC Class Codes: G05B 2219/24085 Analyze, trace fault signals according to tree, table
• CPC Class Codes: G05B 2219/2637 Vehicle, car, auto, wheelchair
• CPC Class Codes: G05B 23/0248 Causal models, e.g. fault tree; digraphs; qualitative physics
• CPC Class Codes: G05B 23/0297 Reconfiguration of monitoring system, e.g. use of virtual sensors; change monitoring method as a response to monitoring results

Abstract

A method is provided for updating a fault tree used in diagnosis of a condition of a machine. The fault tree is a sequence of test modules. Each of the test modules is assigned a confidence score indicating the likelihood that the test module will lead to a diagnosis. The method comprising the steps of obtaining service data from a plurality of service occasions for like machines, revising the confidence score for at least one test module in the fault tree based on the service data; and revising the sequence of the test modules in the fault tree based on the revised confidence score(s). The sequence is revised such that the most likely modules to result in a diagnosis are listed first, and the least likely ones are listed last. The re-ordering is based on feedback from actual service instances in the field, and thus is more likely to reflect real-world conditions. The result is that service technicians using the revised fault trees work more efficiently, at least on a statistical basis.

Claims

1. A method for updating a fault tree used in diagnosis of a condition of a machine, the fault tree comprising a sequence of test modules, each of the test modules being assigned a confidence score, the confidence score representing a probability that the associated test module will lead to a correct diagnosis of the machine condition, the method comprising the steps of:

obtaining service data from a plurality of service occasions for like machines;

revising the confidence score for at least one test module in the fault tree based on the service data; and

revising the sequence of the test modules in the fault tree based on the revised confidence score(s).

2. The method of claim 1, wherein the service data is obtained from a plurality of geographically distributed service facilities.

3. The method of claim 1, wherein the confidence scores are revised by a human operator.

4. The method of claim 1, wherein the confidence scores are revised by a computing device processing the service data using an algorithm embodied as a series of machine-readable instructions.

5. The method of claim 1, wherein the revising step comprises the step of rearranging the test modules into an order in which the sequence of test modules is from the module with the highest confidence score to the lowest confidence score.

6. The method of claim 1, further comprising the step of distributing the revised fault tree to a plurality of geographically distributed service technicians for the machine.

7. The method of claim 1, wherein the machine comprises a component of a motorized vehicle.

8. The method of claim 1, wherein the machine comprises an internal combustion engine or component thereof.

9. A method for updating a fault tree used in diagnosis of a condition of a machine, the fault tree comprising a sequence of test modules, each of the test modules being assigned a confidence score, the method comprising the steps of:

obtaining service data from a plurality of service occasions for like machines;

revising the confidence score for at least one test module in the fault tree based on the service data; and

revising the sequence of the test modules in the fault tree based on the revised confidence score(s);

wherein at least one test module in the fault tree is assigned a technician level score in addition to the confidence score.

10. The method of claim 9, wherein each test module in the fault tree is assigned a technician level score in addition to the confidence score.

11. A method for updating a fault tree used in diagnosis of a condition of a machine, the fault tree comprising a sequence of test modules, each of the test modules being assigned a confidence score, the method comprising the steps of:

obtaining service data from a plurality of service occasions for like machines;

revising the confidence score for at least one test module in the fault tree based on the service data; and

revising the sequence of the test modules in the fault tree based on the revised confidence score(s);

wherein at least one test module in the fault tree is assigned an access number in addition to the confidence score, the access number indicating the number of times a technician accessed the test module.

12. The method of claim 11, wherein each test module in the fault tree is assigned an access number in addition to the confidence score, the access number indicating the number of times a technician accessed the test module.

13. A system for generating a revised fault tree for a machine using statistical feedback, comprising:

a computer system having a memory storing a fault tree;

a database containing service data from a plurality of prior service occasions for like machines, the service occasions associated with the fault tree;

a terminal for providing human access to the fault tree and the database;

wherein the fault tree comprises a plurality of test modules each assigned a confidence score and wherein the confidence score is revised for at least one test module in the fault tree based on the service data and wherein the sequence of the test modules in the fault tree is revised based on the revised confidence score(s).

14. The system of claim 13, wherein the fault tree is revised by rearranging the test modules into an order in which the sequence of test modules is from the module with the highest confidence score to the lowest confidence score.

15. The system of claim 13, wherein at least one test module in the fault tree is assigned a technician level score in addition to the confidence score.

16. The system of claim 15, wherein each test module in the fault tree is assigned a technician level score in addition to the confidence score.

17. The system of claim 13, wherein at least one test module in the fault tree is assigned an access number in addition to the confidence score, the access number indicating the number of times a technician accessed the test module.

18. The system of claim 17, wherein each test module in the fault tree is assigned an access number in addition to the confidence score, the access number indicating the number of times a technician accessed the test module.

19. The system of claim 13, wherein the system distributes the revised fault tree to a plurality of geographically distributed service technicians for the machine.

20. The system of claim 19, wherein the distribution of the revised fault tree is performed electronically.

21. The system of claim 13, wherein system performs a revision of the fault tree on a periodic basis.

22. The system of claim 13, wherein the machine comprises a component of a motorized vehicle.

23. The system of claim 13, wherein the machine comprises an internal combustion engine or component thereof.

24. A system for generating a revised fault tree for use by a technician in diagnosing a condition of a machine using statistical feedback, comprising:

a computer system having a memory storing a fault tree;

a database containing service data from a plurality of prior service occasions for like machines;

a set of machine instructions executed by the computer system wherein the instructions access the service data and revise a confidence score for at least one test module in the fault tree based on the service data;

the instructions further comprising instructions revising the sequence of the test modules in the fault tree based on the revised confidence score(s).

25. The system of claim 24, wherein the fault tree is revised by rearranging the test modules into an order in which the sequence of test modules is from the module with the highest confidence score to the lowest confidence score.

26. The system of claim 24, wherein at least one test module in the fault tree is assigned a technician level score in addition to the confidence score.

27. The system of claim 26, wherein each test module in the fault tree is assigned a technician level score in addition to the confidence score.

28. The system of claim 24, wherein at least one test module in the fault tree is assigned an access number in addition to the confidence score, the access number indicating the number of times a technician accessed the test module.

29. The system of claim 28, wherein each test module in the fault tree is assigned an access number in addition to the confidence score, the access number indicating the number of times a technician accessed the test module.

30. The system of claim 24, wherein the system distributes the revised fault tree to a plurality of geographically distributed service technicians for the machine.

31. The system of claim 24, wherein the distribution of the revised fault tree is performed electronically.

32. The system of claim 24, wherein the system performs a revision of the fault tree on a periodic basis.

33. The system of claim 24, wherein the machine comprises a component of a motorized vehicle.

34. The system of claim 24, wherein the machine comprises an internal combustion engine or component thereof.