Method for mapping alterations in system state to knowledge base objects in a persistent repository-resident knowledge base

• US 6,535,864 B1
• Filed: 08/05/1999
• Issued: 03/18/2003
• Est. Priority Date: 08/05/1999
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Zahn, Karl Theodore
• Primary Examiner(s): Follansbee, John A.
• Assistant Examiner(s): Booker, Kelvin
• Application Number:
  US09/368,784
• Time in Patent Office: 1,321 Days
• Field of Search: 706/45, 706/47, 706/48, 706/46, 706/3, 706/4, 706/8, 706/14, 700/49
• US Class Current: 706/47
• CPC Class Codes: G06N 5/04 Inference or reasoning models

Abstract

A method is provided in a computer system executing a repository program and having a storage means for mapping alterations in system state to rules, both of which are part of an object-oriented model resident in a persistent repository. The method includes storing in the persistent storage means the model comprising a set of rules and a set of facts defining event states, both of which are stored as objects. The set of rules and said set of facts comprise an object-oriented representation of the model. Next, a set of commands representing an extensible inference engine are loaded as meta objects into the persistent storage. The method accepts as inputs events representing alterations in the set of facts. All of the events are retained and the events are mapped to the set of rules for deriving a list of affected rules, which are evaluated to determine if they have been qualified. Only those affected rules determined as qualified are saved for further processing.

Claims

1. In a computer system executing a repository program and having a storage means, a method for mapping alterations in system state to rules, both of which are part of an object-oriented model of the domain resident in a persistent repository, said method comprising:

a. storing in said persistent storage means said model comprising a set of rules sad a set of facts defining event states, both of which are stored as objects, wherein said set of rules and said set of facts comprise an object-oriented representation of said model;

b. loading as meta objects fn said persistent storage a set of commands representing an extensible inference engine;

c. accepting as inputs to said method events representing alterations in said set of facts;

d. retaining all of said events wherein said step of retaining comprises instantiating an AlteredEvent Class, which retains all of said events; and

wherein said step of retaining further comprises determining if an accepted input represents an event, and if so;

adding an event object to a list of changed event objects retained by said instantiation of said AlteredEvent Class;

e. mapping said events to said set of rules for deriving a list of affected rules;

f. evaluating said list of affected rules to determine if they have been qualified, and if so;

g. saving for further processing only those affected rules determined as qualified in the preceding step, said saving comprising instantiating an AgendaQueue Class to retain only those affected rules determined as qualified.

2. The method as in claim 1 wherein said step of mapping comprises traversing said list of changed event objects to obtain a list of affected rules for each of said changed event objects.

3. The method as in claim 2 further comprises for each affected rule in said list of affected rules, testing s rule condition object belonging to said affected rule and associated with said changed event object to determine if said rule condition object is satisfied by said changed event, and if so marking said rule condition object as satisfied.

4. The method as in claim 3 further comprises traversing all affected rules to determine if all rule condition objects belonging to each of said affected rules is marked as satisfied.

5. The method as in claim 4 wherein if all rule condition objects belonging to each of said affected rules is marked as satisfied, then marking each of such affected rules as satisfied.

6. The method as in claim 5 wherein said step of saving further comprises retaining in an instance of an AgendaQueue Class each one of said affected rules marked as satisfied.

7. A storage medium encoded with machine-readable computer program code for use in a computer system executing a repository program and having a storage means, said computer program being a method for mapping alterations in system state rules, both of which are part of an object-oriented model of the domain resident in a persistent repository, wherein, when the computer program code is executed by a computer, the computer performs the steps of:

a. storing in said persistent storage means said model comprising a set of rules and a set of facts defining event states, both of which are stored as objects, wherein said set of rules and said set of facts comprise an object-oriented representation of said model;

b. loading as meta objects in said persistent storage a set of commands representing an extensible inference engine;

c. accepting as inputs to said method events representing alterations in said set of facts;

d. retaining all of said events; and

wherein said step of further comprises determining if an accepted input represents an event, and if so;

adding an event object to a list of changed event objects retained by said instantiation of said AlteredEvent Class;

e. mapping said events to said set of rues for deriving a list of affected rules;

f. evaluating said list of affected rules to determine if they have been qualified, and if so;

g. saving for further processing only those affected rules determined as qualified in the preceding step, said saving comprising instantiating an AgendaQueue Class to retain only those affected rules determined as qualified.

8. A storage medium as in claim 7 wherein said step of mapping comprises traversing said list of changed event objects to obtain a list of affected rules for each of said changed event objects.

9. A storage medium as in claim 8 further comprises for each affected rule in said list of affected rules, testing a rule condition object belonging to said affected rule and associated with said changed event object to determine if said rule condition object is satisfied by said changed event, and if so marking said rule condition object as satisfied.

10. A storage medium as in claim 9 further comprises traversing all affected rules to determine if all rule condition objects belonging to each of said affected rules is marked as satisfied.

11. A storage medium as in claim 10 wherein if all rule condition objects belonging to each of said affected rules is marked as satisfied, then marking each of such affected rules as satisfied.

12. A storage medium as in claim 11 The method as in claim 8 wherein said step of saving further comprises retaining in an instance of an AgendaQueue Class each one of said affected rules marked as satisfied.

13. In a computer system executing a repository program and having a storage means, a method for mapping alterations in system state to rules, both of which are part of an object-oriented model of the domain resident in a persistent repository, said method comprising:

a. storing in said persistent storage means said model comprising a set of rules and a set of facts defining event states, both of which are stored as objects, wherein said set of rules and said set of facts comprise an object-oriented representation of said model;

b. grouping said set of rules as instances of a RuleGroup Class;

c. allowing a user to enable said instances of said RuleGroup Class instantiated in the preceding step;

d. loading as mete objects in said persistent storage a set of commands representing an extensible inference engine;

e. accepting as inputs to said method events representing alterations in said set of facts;

f. retaining all of said events;

g. mapping said events to said set of rules for deriving a list of affected rules;

h. evaluating said list of affected rules to determine if they have been qualified, and if so; and

,

i. saving for further processing only those affected rules determined as qualified and belonging to said enabled instance of said RuleGroup Class.