Claims
- 1. A system for optimizing polymer production scheduling, the system comprising:
an input, operable to receive optimization input information; a model of a polymer production system, wherein the model comprises one or more transition models representing transition behavior of the polymer production system; an optimizer, operable to execute the model using the received optimization input information to generate an optimized polymer production schedule; and an output, operable to output the generated optimized polymer production schedule, wherein the optimized polymer production schedule is usable to manage polymer production with a polymer production system.
- 2. The system of claim 1, wherein the optimization input information comprises one or more of:
economic information; demand information; demand forecast information; customer order information; customer book information; customer priority information; inventory information; cost information; production information; product pricing information; product book information; product value information; order value information; line map information; capacity limits; scheduling horizon; and ambient conditions.
- 3. The system of claim 2, wherein the cost information includes one or more of:
cost of manufacturing products; cost of transitions between products; cost of storing products prior to delivery; and cost of missing demands.
- 4. The system of claim 2,
wherein the optimization input information comprises hypothetical scenario information; and wherein the optimized polymer production schedule is usable to analyze business and production strategies based on the hypothetical scenario information.
- 5. The system of claim 1, wherein the optimization input information comprises one or more of:
an objective; and one or more constraints; wherein the optimizer is operable to use the objective and one or more constraints to generate the optimized polymer production schedule; and wherein the optimized polymer production schedule attempts to meet the objective subject to the one or more constraints.
- 6. The system of claim 1, further comprising:
a controlled polymer production system, wherein the controlled polymer production system comprises:
a polymer production system; and an advanced process control, coupled to the polymer production system, and operable to control operations of the polymer production system.
- 7. The system of claim 6, wherein the output is further operable to provide the optimized polymer production schedule to the advanced process control, and wherein the advanced process control is operable to schedule polymer production by the polymer production system in accordance with the optimized polymer production schedule.
- 8. The system of claim 7,
wherein the input is further operable to receive updated optimization input information; wherein the optimizer is further operable to execute the model using the received updated optimization input information to generate an updated optimized polymer production schedule; wherein the output is further operable to output the updated optimized polymer production schedule to the advanced process control; and wherein the advanced process control is operable to re-schedule polymer production by the polymer production system in accordance with the updated optimized polymer production schedule.
- 9. The system of claim 8, wherein the input is operable to receive said updated optimization input information in response to one or both of:
an event; and a time.
- 10. The system of claim 1, wherein the optimized polymer production schedule comprises one or more of:
grade levels to produce for one or more products; quantities to produce of the one or more products; when to produce each of the one or more products; when to transition between the one or more products; and which process line to use for each of the one or more products.
- 11. The system of claim 1, wherein the optimized polymer production schedule sequences manufacturing orders to maximize gross profit margin.
- 12. The system of claim 1, wherein said optimizer is operable to generate an optimized polymer production schedule by performing a Large-step Markov Chain Optimization Search in a space of possible schedules.
- 13. The system of claim 1, wherein said optimizer is operable to generate an optimized polymer production schedule by:
a) determining an initial schedule; b) determining a search space for the initial schedule specifying a plurality of large-scale permutations of the initial schedule; c) performing a large scale permutation of the initial schedule based on the search space to generate an intermediate schedule; d) performing a local search around the intermediate schedule to generate a local schedule solution; e) determining if the local schedule solution is accepted;
if the local schedule solution is accepted,
f) if the local schedule solution is better than a current best schedule, setting the current best schedule to the local schedule; g) setting the initial schedule to the local schedule solution; and h) returning to step b); if the local schedule solution is not accepted,
i) determining if ending conditions are met; and j) if ending conditions are not met, returning to step c); and k) setting the optimized polymer production schedule to the current best schedule.
- 14. The system of claim 13, wherein said optimizer is further operable to generate an optimized polymer production schedule by:
determining acceptance criteria for the local schedule solution.
- 15. The system of claim 14, wherein said determining acceptance criteria for the local schedule solution is performed prior to e).
- 16. The system of claim 14, wherein said determining acceptance criteria for the local schedule solution is performed prior to b).
- 17. The system of claim 14, wherein said determining acceptance criteria for the local schedule solution comprises:
determining a probability of acceptance of the local schedule solution based on one or more of:
cost of the initial schedule; cost of the local schedule solution; and a time-dependent metric;
- 18. The system of claim 17, wherein said determining a probability of acceptance of the local schedule solution comprises using a simulated annealing approach to determine said probability.
- 19. The system of claim 13,
wherein said performing a large scale permutation of the initial schedule based on the search space to generate an intermediate schedule comprises:
performing a block insertion of schedule steps, wherein a block of one or more consecutive schedule steps are moved from a source slot to a destination slot in the initial schedule, thereby generating the intermediate schedule.
- 20. The system of claim 19, wherein said determining a search space for the initial schedule comprises:
determining a range of block sizes, wherein each block size indicates a number of schedule steps comprised in the block of schedule steps; determining a range of source slots, wherein each source slot indicates a possible starting point for the block of one or more consecutive schedule steps; and determining a range of destination slots, wherein each destination slot indicates a possible insertion point for the block insertion; wherein said optimizer is operable to iterate through at least a portion of each of the range of block sizes, the range of source slots, and the range of destination slots for each initial schedule, and wherein each iteration corresponds to a large-scale permutation of the initial schedule.
- 21. The system of claim 13, wherein said performing a local search around the intermediate schedule to generate a local schedule solution comprises:
performing a Lin-Kernighan search around the intermediate schedule to generate the local schedule solution.
- 22. The system of claim 13, wherein said determining if ending conditions are met comprises one or more of:
determining if the search space for the initial schedule has been exhausted; determining if a maximum number of iterations has been performed; and determining if a maximum time period has elapsed.
- 23. The system of claim 13, wherein the initial schedule, the intermediate schedule, the local schedule solution, and the optimized polymer production schedule are each analyzable via one or more of:
lateness distribution; key cost factors; and key variable phenomena and characteristics.
- 24. The system of claim 1, wherein the model comprises one or more predictive models.
- 25. The system of claim 1, wherein the model comprises one or more of:
an analytic model; an empirical model; a rule-based model; and a simulation.
- 26. The system of claim 1, wherein the model includes one or more of:
an objective; and one or more constraints; wherein the optimizer is operable to use the objective and one or more constraints to generate the optimized polymer production schedule; and wherein the optimized polymer production schedule attempts to meet the objective subject to the one or more constraints.
- 27. The system of claim 1, wherein the model of the polymer production system comprises a model of a controlled polymer production system, wherein the model of the controlled polymer production system comprises:
a model of an advanced process control, operable to model control operations of the polymer production system.
- 28. A system for optimizing polymer production scheduling, the system comprising:
means for receiving optimization input information; means for executing a model of a polymer production system using the received optimization input information to generate an optimized polymer production schedule, wherein the model includes one or more transition models representing transition behavior of the polymer production system; and means for outputting the generated optimized polymer production schedule, wherein the optimized polymer production schedule is usable to manage polymer production with a polymer production system.
- 29. The system of claim 28, further comprising:
a controlled polymer production system, wherein the controlled polymer production system comprises:
a polymer production system; and an advanced process control, coupled to the polymer production system, and operable to control operations of the polymer production system; and means for providing the optimized polymer production schedule to the advanced process control, wherein the advanced process control is operable to schedule polymer production by the polymer production system in accordance with the optimized polymer production schedule.
- 30. The system of claim 29,
wherein said means for receiving optimization input information is further operable to receive updated optimization input information; wherein said means for executing a model of a polymer production system is further operable to execute the model using the received updated optimization input information to generate an updated optimized polymer production schedule; and wherein said means for outputting the generated optimized polymer production schedule is further operable to output the updated optimized polymer production schedule to the advanced process control; and wherein the advanced process control is further operable to re-schedule polymer production by the polymer production system in accordance with the updated optimized polymer production schedule.
- 31. A method for optimizing polymer production scheduling, the method comprising:
receiving optimization input information; an optimizer executing a model of a polymer production system using the received optimization input information to generate an optimized polymer production schedule, wherein the model includes one or more transition models representing transition behavior of the polymer production system; and outputting the generated optimized polymer production schedule, wherein the optimized polymer production schedule is usable to manage polymer production with a polymer production system.
- 32. The method of claim 31, wherein the optimization input information comprises one or more of:
an objective; and one or more constraints; wherein said optimizer executing the model using the received optimization input information to generate an optimized polymer production schedule optimizer comprises:
the optimizer using the objective and one or more constraints to generate the optimized polymer production schedule; and wherein the optimized polymer production schedule attempts to meet the objective subject to the one or more constraints.
- 33. The method of claim 31, further comprising:
providing the optimized polymer production schedule to an advanced process control; the advanced process control scheduling polymer production by a polymer production system in accordance with the optimized polymer production schedule.
- 34. The method of claim 33, further comprising:
receiving updated optimization input information; the optimizer executing the model using the received updated optimization input information to generate an updated optimized polymer production schedule; outputting the updated optimized polymer production schedule to the advanced process control; and the advanced process control re-scheduling polymer production by the polymer production system in accordance with the updated optimized polymer production schedule.
- 35. The method of claim 31, wherein said optimizer executing the model using the received optimization input information to generate an optimized polymer production schedule comprises:
performing a Large-step Markov Chain Optimization Search in a space of possible schedules.
- 36. The method of claim 31, wherein said optimizer executing the model using the received optimization input information to generate an optimized polymer production schedule comprises:
a) determining an initial schedule; b) determining a search space for the initial schedule specifying a plurality of large-scale permutations of the initial schedule; c) performing a large scale permutation of the initial schedule based on the search space to generate an intermediate schedule; d) performing a local search around the intermediate schedule to generate a local schedule solution; e) determining if the local schedule solution is accepted;
if the local schedule solution is accepted,
f) if the local schedule solution is better than a current best schedule, setting the current best schedule to the local schedule; g) setting the initial schedule to the local schedule solution; and h) returning to step b); if the local schedule solution is not accepted,
i) determining if ending conditions are met; and j) if ending conditions are not met, returning to step c); and k) setting the optimized polymer production schedule to the current best schedule.
- 37. A carrier medium which stores program instructions which are executable to perform:
receiving optimization input information; executing a model of a polymer production system using the received optimization input information to generate an optimized polymer production schedule, wherein the model includes one or more transition models representing transition behavior of the polymer production system; and outputting the generated optimized polymer production schedule, wherein the optimized polymer production schedule is usable to manage polymer production with a polymer production system.
- 38. The carrier medium of claim 37,
wherein the optimization input information comprises hypothetical scenario information; and wherein the optimized polymer production schedule is usable to analyze business and production strategies based on the hypothetical scenario information.
- 39. The carrier medium of claim 37, wherein said optimizer executing the model using the received optimization input information to generate an optimized polymer production schedule comprises:
performing a Large-step Markov Chain Optimization Search in a space of possible schedules.
- 40. The carrier medium of claim 46, wherein said optimizer executing the model using the received optimization input information to generate an optimized polymer production schedule comprises:
a) determining an initial schedule; b) determining a search space for the initial schedule specifying a plurality of large-scale permutations of the initial schedule; c) performing a large scale permutation of the initial schedule based on the search space to generate an intermediate schedule; d) performing a local search around the intermediate schedule to generate a local schedule solution; e) determining if the local schedule solution is accepted;
if the local schedule solution is accepted,
f) if the local schedule solution is better than a current best schedule, setting the current best schedule to the local schedule; g) setting the initial schedule to the local schedule solution; and h) returning to step b); if the local schedule solution is not accepted,
i) determining if ending conditions are met; and j) if ending conditions are not met, returning to step c); and k) setting the optimized polymer production schedule to the current best schedule.
PRIORITY CLAIM
[0001] This application claims benefit of priority of U.S. provisional application Serial No. 60/382,856 titled “Polymer Production Scheduling Using Transition Models” filed May 23, 2002, whose inventors are Chih-An Hwang, Kadir Liano, Yong-Zai Lu, Willie Putrajaya and Carl Schweiger.
Provisional Applications (1)
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Number |
Date |
Country |
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60382856 |
May 2002 |
US |