Systems and methods for optimizing a production facility

• US 6,633,790 B2
• Filed: 01/29/2001
• Issued: 10/14/2003
• Est. Priority Date: 01/29/2001
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Gartstein, Yuri
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): SHECHTMAN, SEAN P
• Application Number:
  US09/771,740
• Publication Number:
  US 20020103559A1
• Time in Patent Office: 988 Days
• Field of Search: 700/97, 700/99-103, 700/111, 700/95, 705/7-9
• US Class Current: 700/99
• CPC Class Codes: G06Q 10/04 Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem" market predictions or forecasting for commercial activities G06Q30/0202

Abstract

Systems and methods are provided for optimizing a production facility that includes workstations for producing products. The method involves utilizing an objective function to find optimal production rates of the products.

Claims

1. A method for optimizing a production facility having a plurality of workstations for producing products, the method comprising the steps of

for each product, finding a bottleneck rate representing the inverse of a maximum effective processing time of one of workstations of the plurality of workstations;

for each product, associating a production rate; and

computing optimal production rates for the plurality of workstations by utilizing an objective function of the bottleneck rates and the production rates.

2. The method of claim 1, wherein, in the step of computing, the optimal production rates substantially maximize the objective function.

3. The method of claim 2, wherein, in the step of computing, the objective function is substantially maximized subject to capacity constraints of the at least one workstation.

4. The method of claim 1, wherein, in the step of computing, the objective function of the bottleneck rates and the production rates is a linear function of the inverse of the bottleneck rates.

5. The method of claim 1, wherein, in the step of computing, the objective function of the bottleneck rates and the production rates is a linear function of the production rates.

6. The method of claim 1, wherein, in the step of computing, the objective function is a sum of products of the production rates and the inverse of the bottleneck rates.

7. The method of claim 1, wherein, in the step of finding, the at least one workstation is a print shop workstation.

8. The method of claim 1, wherein, in the step of finding, the at least one workstation includes at least one machine or processing operator.

9. The method of claim 1, wherein, in the step of finding, the at least one workstation includes a machine for manufacturing image forming systems.

10. The method of claim 1, wherein, in the step of computing, each product is associated with an optimal production rate computed by utilizing the objective function.

11. The method of claim 10, further comprising manufacturing the products at the optimal production rates associated therewith.

12. The method of claim 1, further comprising re-calculating optimal production rates to reflect a changing status of the facility and of jobs in the facility.

13. A production facility comprising

a) at least one workstation for producing products, each product having a bottleneck rate representing the inverse of a maximum effective processing time of the at least one workstation;

and

b) a central processor having instructions to input the bottleneck rate of each product, and to output an optimal production rate for each product;

wherein the instructions utilize an objective function of the bottleneck rate of each product to output the optimal production rate for each product.

14. The production facility of claim 13, wherein the optimal production rate output by the central processor influences a production rate of the at least one workstation.

15. The production facility of claim 13, wherein the instructions include a subroutine for maximizing the objective function to obtain the optimal production rate for each product.

16. The production facility of claim 13, wherein the instructions include a subroutine for maximizing the objective function to obtain the optimal production rate for each product subject to capacity constraints of the at least one workstation.

17. A method for optimizing a production facility that produces Np products using Nw workstations, where Np and Nw are natural numbers, the method comprising the steps of:

for each of the Np products, finding a bottleneck rate representing the inverse of a maximum effective processing time of the Nw workstations, the bottleneck rate of product j being denoted by r_jb, where j=1,2, . . . , or Np;

for each of the Np products, associating a production rate, the production rate of product j being denoted by u_j, where j=1,2, . . . , or Np; and

computing optimal production rates by utilizing an objective function of r_1b, r_2b, . . . , r_Npb, and u₁, u₂, . . . , u_Np.

18. The method of claim 17, wherein, in the step of computing, the objective function is substantially equal to Σ

_ju_j/r_jb.

19. The method of claim 18, wherein the optimal production rates substantially maximize the objective function subject to capacity constraints.