Method and system for analyzing throughput

• US 7,398,132 B2
• Filed: 01/06/2006
• Issued: 07/08/2008
• Est. Priority Date: 01/06/2006
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Steinhilper, Eric A.
• Primary Examiner(s): Barnes-Bullock; Crystal
• Application Number:
  US11/327,121
• Publication Number:
  US 20070162163A1
• Time in Patent Office: 914 Days
• Field of Search: 700/95, 700/108, 700/111, 702/182, 702/183, 702/185, 414/273
• US Class Current: 700/111
• CPC Class Codes: G05B 19/4184 characterised by fault tolerance, reliability of production system
• CPC Class Codes: G05B 2219/31434 Zone supervisor, collects error signals from, and diagnoses different zone
• CPC Class Codes: G05B 2219/32322 Machines with least frequency of errors
• CPC Class Codes: G05B 2219/37525 Mean, average values, statistical derived values
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Described is a method and system for analyzing throughput of a production line. The method includes selecting among the stations, a set of susceptible stations that are affected by at least one selected event, ranking the susceptible stations with respect to a selected event and the predetermined criteria to determine an ordered list of more susceptible stations, altering the selected events to generate a new set of events, reranking the susceptible stations with respect to the selected events comprising the new event to determine a new ordered list of more susceptible stations and determining the most susceptible station based on a comparison criterion of the original ordered list of more susceptible stations and the new ordered list of more susceptible stations.

Claims

1. A throughput analysis method for a manufacturing line including a plurality of machines, each configured to generate event codes which are input to the throughput analysis, the throughput analysis method comprising:

calculating a first throughput value for the plurality of machines based on the input;

ranking the plurality of machines and their associated event codes according to their effect on throughput;

altering a value of a first event code associated with a first machine to generate an altered first event code for a new event code input;

recalculating a second throughput value based on the new event code input; and

comparing the first throughput value with the second throughput value to generate a weight of the first event code on the first throughput value.

2. A method as recited in claim 1 wherein input for the calculating step is derived from:

calculating with a mathematical algorithm the mean time to repair for the plurality of machines and from that calculating repair times for the different codes representing breakdowns; and

calculating with a mathematical algorithm mean count between events for the plurality of machines and from that calculating the mean time between failures and mean count between failures.

3. A method as recited in claim 1 wherein calculating a first throughput value, comprises:

processing by a discrete event simulation.

4. A method as recited in claim 1 wherein the recalculating step comprises:

recalculating with a mathematical algorithm from the mean time to repair for the plurality of machines a new set of event codes and their corresponding repair times; and

recalculating with a mathematical algorithm from the mean count between events for the plurality of machines a new set of event codes and the corresponding number of parts made between events.

5. A method as recited in claim 4 wherein recalculating with the mathematical algorithm, comprises:

processing by a discrete event simulation.

6. A method as recited in claim 1 further comprising determining sensitivity, the method further comprising:

comparing the first throughput value with the second throughput value to generate a percentage difference in throughput;

comparing the difference between the first event code having a repair time and the altered first event code having a repair time to generate the percentage difference in repair time; and

dividing the percentage difference in throughput by the percentage difference in repair time to generate the sensitivity.

7. A method as recited in claim 1 wherein altering a value of a first event code comprises:

changing a repair time of the first event code.

8. A method as recited in claim 1 wherein altering a value of a first event code comprises:

eliminating the first event code.

9. A method as recited in claim 1 wherein altering a value of a first one event code to generate an altered event code further comprises:

altering a plurality of event codes values to generate a plurality of altered event code values.

10. A method for evaluating stations of a system for improvability according to predetermined criteria, the method comprising;

selecting among the stations, a set of susceptible stations that are affected by at least one selected event;

ranking the susceptible stations with respect to a selected event and the predetermined criteria to determine an ordered list of more susceptible stations;

altering the selected events to generate a new set of events;

reranking the susceptible stations with respect to the selected events comprising the new event to determine a new ordered list of more susceptible stations; and

determining the most susceptible station based on a comparison criterion of the original ordered list of more susceptible stations and the new ordered list of more susceptible stations.

11. A method as recited in claim 10 wherein determining comprises evaluating with a decision-making tool.

12. The method of claim 11, wherein the decision-making tool comprises a discrete event simulation.

13. The method of claim 10, wherein the comparison criterion comprises cost.

14. The method of claim 10, wherein the comparison criterion comprise maintenance priorities.

15. The method of claim 10, wherein the comparison criterion comprises production throughput.

16. The method of claim 10 wherein a station comprises at least one manufacturing machine.

17. A manufacturing line system comprising a plurality of machines configured to generate event codes as input, the input delivered to a computational subsystem, the system comprising:

a calculating module for calculating a first throughput value for the plurality of machines based on the event code input;

a ranking module for ranking the plurality of machines and their associated the event codes according to their effect on throughput;

an altering module for altering a value of a first event code to generate an altered first event code to generate new event code input;

a recalculating module for recalculating the second throughput value based on the new event code input; and

a comparing module for comparing the first throughput value with the second throughput value to generate an influence value for the altered event code inputs on the first throughput value.

18. A system as recited in claim 17 wherein the calculating module comprises:

a discrete event simulation module.

19. A manufacturing line system as recited in claim 18 wherein the manufacturing line is for the manufacture of motorized vehicles.

20. A system as recited in claim 17 wherein the comparing module comprises:

a decision-making tool module.