US5040123A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expert system scheduler
Assignee: Motors Liquidation Co
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Filing: 1989-09-08
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Granted: 1991-08-13
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Expires: 2009-09-08
Abstract
Abstract An expert system scheduler is disclosed which uses heuristics developed by an experienced factory scheduler. The scheduler uses these heuristics to generate schedules. Forward and backward scheduling is used at different stages of the schedule generation process.
Inventors
- 👤 Karon A. Barber
- 👤 David H. Osterfeld
- 👤 Kenneth L. Burridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:39
CPC Classifications
G; G06; G06Q; G06Q10/00; G06Q10/06; G05; G05B; G05B19/00; G05B19/02; G05B19/418; G05B19/41865; G06Q10/08; G06Q10/087; G06Q10/0872; G06Q10/08726; G06Q10/0877; G05B2219/00; G05B2219/30; G05B2219/32; G05B2219/32252; G05B2219/33; G05B2219/33002; Y; Y02; Y02P; Y02P90/00; Y02P90/02; Y02P90/80; Y10; Y10S; Y10S706/00; Y10S706/902; Y10S706/903; Y10S706/904
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
162 words
A computer implemented method of scheduling a plurality of machine operations in a predetermined sequence in a factory containing a plurality of machines and a factory control system which controls the machines in accordance with the schedule, comprising the steps of: a. constructing a computer model of the factory comprising data relating to the production of parts including inventory, operations, machines, and at least one customer order, b. scheduling the machine operations necessary to produce the parts in the customer order in the reverse order of routing with the last operation being scheduled first and the first operation being scheduled last, c. modifying the schedule defined in scheduling step b. by removing machine operations which are unnecessary due to existing factory part inventory to thereby better utilize available machine capacity, d. further modifying the schedule produced in schedule modifying step c. by shifting certain operations forward in time to insure that no operations are scheduled prior to a predetermined build context time.
Claim 2
Dependent Claim
162 words
A computer implemented method of scheduling a plurality of machine operations in a predetermined sequence in a factory containing a plurality of machines and a factory control system which controls the machines in accordance with the schedule, comprising the steps of: a. constructing a computer model of the factory comprising data relating to the production of parts including inventory, operations, machines, and at least one customer order, b. scheduling the machine operations necessary to produce the parts in the customer order in the reverse order of routing with the last operation being scheduled first and the first operation being scheduled last, c. modifying the schedule defined in scheduling step b. by removing machine operations which are unnecessary due to existing factory part inventory to thereby better utilize available machine capacity, d. further modifying the schedule produced in schedule modifying step c. by shifting certain operations forward in time to insure that no operations are scheduled prior to a predetermined build context time.
Claim 3
Dependent Claim
36 words
The invention defined in claim 1 comprising the further step of modifying the schedule produced in schedule modifying step d of claim 1 to include preventive maintenance jobs on machines requiring same during the scheduling horizon.
Claim 4
Dependent Claim
19 words
The invention defined in claim 2 comprising the further step of modifying the schedule to front load the schedule.
Claim 5
Dependent Claim
37 words
The invention defined in claim 1 comprising the further step of modifying the schedule, if lateness is anticipated for customer orders, by removing machine operations which are unnecessary due to existing safety stock to thereby minimize lateness.
Claim 6
Dependent Claim
28 words
The invention defined in claim 1 comprising the further step of modifying the schedule, by forward scheduling the necessary operations to replenish safety stock to a predetermined level.
Claim 7
Dependent Claim
71 words
The invention defined in claim 1 wherein step b comprises the steps of, 1) sorting customer orders by due date, 2) considering each of the sorted orders in sequence, 3) considering each operation required to produce the part in the order in the reverse sequence of routing, 4) selecting a machine capable of performing a given operation, 5) defining a desirable window of time during which the operation can be performed.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-12 | 1995-02-11 | 1995-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-12 | 1999-02-11 | 1999-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-12 | 2003-02-11 | 2003-08-13 | $7700.00 | Window Closed / Lapsed |