US 5,212,791 AGranted

Dynamic scheduling

AssigneeInternational Business Machines Corporation

InventorsRichard G. Damian, Manesh J. Shah

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Abstract

The invention provides a new production scheduling system. The system includes a technique that utilizes a knowledge base system to dynamically schedule production of parts on a plurality of manufacturing machines. The schedule is updated dynamically to conserve synergism with the changing plant environment. The schedule is created to conform with predefined rules to conserve constraints imposed by the machinery to create parts of different specifications. The rules may be hard in that they may be specifiable in mathematical terms or they may be heuristic and soft in that they may be allowed to be relaxed as determined by operators who have learned from experience with the production machinery. Finally, the invention allows interactive monitoring and adjustment of the schedule by an operator including selective seeding of the schedule.

Claims5

Dependent claims

A method for operating a computer system to generate a schedule for a plurality of orders, the schedule having a plurality of slots for orders, the system having an inference engine for processing a set of rules including disposition, strategy and error detection rules, having a production memory for storing the set of rules and having working memory for storing a pool of schedules, comprising the steps of:

(a) forming a current parent schedule in the pool in the working memory having a first slot filled by an order by processing predetermined strategy rules using the inference engine;
(b) generating in the pool in the working memory all possible child schedules for the current parent schedule with each child schedule having at least one more slot filled than the current parent schedule by processing a rule using the inference engine;
(c) calculating error counts for the child schedules which violate the error detection rules by processing the error detection rules using the inference engine;
(d) deleting the current parent schedule from the pool in the working memory by processing a rule using the inference engine;
(e) deleting from the pool in the working memory the child schedules having error counts exceeding a predetermined error count threshold by processing the disposition rules using the inference engine;
(f) determining by processing a rule using the inference engine whether there are any schedules in the pool in the working memory and selecting, by processing a rule using the inference engine, a schedule in the pool, if any exists, as the current parent schedule while leaving the remaining schedules in the pool or ending if there are no schedules in the pool;
and
(g) repeating steps (b) through (f) until a schedule with all slots filled is found which meets the disposition rules by processing a rule using the inference engine.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/920,000Filed 27 Jul 1992 · continuation
Priority: 27 Sep 1989
Granted: 18 May 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

G06Q 10/06
Administration; Management: resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation…
G05B 19/41865
Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible…:…
G06Q 10/0875
Inventory or stock management, e.g. order filling, procurement or balancing against orders: itemisation or classification of parts, supplies or…
G05B 2219/32252
Operator till task planning: scheduling production, machining, job shop