METHOD FOR OPERATING A MANUFACTURING LINE

• US 3,703,725 A
• Filed: 11/02/1970
• Issued: 11/21/1972
• Est. Priority Date: 11/02/1970
• Status: Expired due to Term

• Current Assignee: Earl Raymond Gomersall, Roger Paul Meyer, Susan English Rejmaniak
• Original Assignee: Earl Raymond Gomersall, Roger Paul Meyer, Susan English Rejmaniak
• Inventors: Gomersall, Earl Raymond, Meyer, Roger Paul, Rejmaniak, Susan English
• Primary Examiner(s): Atkinson, Charles E.
• Assistant Examiner(s): Dildine, Jr., R. Stephen
• Application Number:
  US05/086,204
• Time in Patent Office: 750 Days
• Field of Search: 235/150 444/1
• US Class Current: 700/97
• CPC Class Codes: G05B 19/4189 characterised by the transport system
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A manufacturing line has a plurality of work stations. The work stations are ordered into sequential flow points through which work in process flows. The work flow through the sequentially ordered flow points is balanced in an automatic data processing machine by starting at the last flow point in the ordered sequence. In a multiproduct path manufacturing line, the flow points on adjacent product paths are ordered into neighborhoods prior to balancing the manufacturing line.

Claims

1. The method of balancing a manufacturing line having a plurality of product paths through said manufacturing line comprising the steps of establishing the work stations through which the work flows in each product path, ordering said work stations into sequential path points in each product path, ordering the path points in said product paths into a sequence of neighborhoods in said manufacturing line, and balancing in an automatic data processing machine the flow of work in said plurality of product paths in said manufacturing line starting with the last neighborhood in said sequence of neighborhoods.

2. The method of claim 1 of balancing a manufacturing line wherein said neighborhoods are established in the following manner in an automatic data processing machine wherein N is a collection of flow points defining the manufacturing line, P is a product path in said manufacturing line, a flow point i, on product path P is said to have a predecessor in the manufacturing line N if and only if there exists a flow point j in N such that i immediately precedes j on product path P, a neighborhood Ni, in the manufacturing line N is the set of all path points i which have no predecessors in the set;

N ;

i 1 j i- 1 N - Nj ;

i >

1 j 1

3. The method of claim 1 of balancing a manufacturing line wherein said neighborhoods ordered by path pointers.

4. The method of balancing a manufacturing line claimed in claim 3 wherein variables are taken into account in the calculation of the necessary input to each path point to deliver the desired input to the succeeding flow point.

5. The method of balancing a manufacturing line claimed in claim 4 wherein said variables include a scrap factor, a rework factor, and an excess work in process factor.

6. The method of claim 1 wherein the desired output from said manufacturing line is established and the inputs to the path points in said neighborhoods are calculated by neighborhood starting with the last neighborhood in said sequence to provide the necessary input and continuing this calculation to each preceding neighborhood in succession.

7. The method claimed in claim 6 wherein said path points in said product paths are grouped into flow points for adjacent product paths.

8. The method claimed in claim 7 wherein the unit labor cost is calculated at each flow point according to the following manner:

where;

ULC is unit labor cost, VOL is flow point volume, ALR is average labor rate, LS is labor standard, and LP is labor performance.

9. The method of balancing a manufacturing line as claimed in claim 7 wherein a rework-in variable is taken into the calculation for determining the required input to each flow point.

10. The method claimed in claim 9 wherein equipment capacity constraint is taken into account as a variable.

11. The method claimed in claim 10 wherein a capacity simulation is carried out adding equipment required to rebalance a line.

12. The method claimed in claim 9 wherEin a bottleneck flow point is identified and the input of each path point in the bottleneck flow point is ratioed down to drive the achievable output to the end of the manufacturing line.

13. The method claimed in claim 12 wherein a bottleneck is identified at a multi-use flow point and path point inputs are ratioed down.

14. The method claimed in claim 9 wherein work in process is allocated to the particular path points in the same ratio as the input desired work in process is calculated.

15. The method of claim 9 wherein the material cost at each flow point is calculated with the cost of entered material divided by the number of good units proceeding to next sequential flow point.

16. The method claimed in claim 9 wherein a number is retrieved from a random number generator as each piece of work enters the first flow point of the product path, comparing this random number to the input values of yield and rework-out percentage, and each piece is processed down the product path until it is scrapped or enters the end of the path to simulate the total pieces of rework-in at each flow point.

17. The method claimed in claim 16 wherein the yields and rework-out percentage is calculated for each flow point.

18. Apparatus for balancing a model of a manufacturing line having a plurality of product paths with the work stations in said product paths ordered into a sequence of path points along each product path comprising means for ordering the path points in said product paths into a sequence of neighborhoods and means for balancing the flow of work in said plurality of product paths in said manufacturing line starting with the last neighborhood in said sequence of neighborhoods.