Peoplesoft, Inc.

Michael J Deale

Monte Zweben

Mark A Vershel

Eugene D Davis

Christophe E Pettus

Brian L Daun

A schedule for a complex activity is obtained by a scheduling system using a method of constraint-based iterative repair. A predetermined initial schedule is iteratively repaired, repairs being made during each iteration only to portions of the schedule that produce a constraint violation, until an acceptable schedule is obtained. Since repairs are made to the schedule only to repair violated constraints, rather than to the entire schedule, schedule perturbations are minimized, thereby reducing problems with the dynamic performance of the scheduling system and minimizing disruption to the smooth operation of the activity. All constraints on the scheduling activity can be evaluated simultaneously to produce a solution that is near optimal with respect to all constraints. In particular, consumable resource constraints can be evaluated simultaneously with other constraints such as, for example, reusable resource constraints, temporal constraints, state constraints, milestone constraints and preemptive constraints. The scheduling system of the invention is much quicker than previous scheduling systems that use, for example, constructive scheduling method. The system of the invention can also be easily modified to add, delete or modify constraints. Because of the minimization of schedule perturbation, coupling of all constraints, speed of operation, and ease of modification, the scheduling system of the invention is particularly useful for scheduling applications that require frequent and rapid rescheduling.

Iterative repair optimization with particular application to scheduling for integrated capacity and inventory planning

The invention facilitates modeling of an enterprise. A model developer uses a high-level modeling language to describe the enterprise with constructs that are more readily accessible to the model developer than those used in other previous modeling languages. The high-level description is translated into a low-level description that can more readily be used by a processing device to dynamically exercise the model. The constructs of the modeling language shield the model developer from many of the mundane tasks associated with maintaining data integrity in complex data structures. Of particular importance, the modeling language includes data constructs that make it easy to track and maintain data that changes during execution of a program, without considerable effort on the part of the model developer. These data constructs can be used to restore various states of the modeled enterprise during execution of the program, either automatically or at the direction of a user. The invention is particularly useful for modeling a complex enterprise, the operation of which is characterized by a large body of information. The invention can be used, for example, to develop a scheduling system for scheduling a complex activity and revising the schedule as necessary to accommodate changed circumstances. However, the invention is broadly applicable to modeling of any enterprise.

Net change management for object-oriented modeling

The invention enables multiple users to simultaneously access and change the contents of a database in a flexible manner. Each user interacts with a working copy of a master copy of the database. The contents of each of the working copies of the database can be accessed and manipulated so that the contents of the working copy of the database can be revised. Each user has control over whether to the 'publish' revisions made to the contents of that user's working copy of the database, i.e., write the revisions to the master copy and present other users with the option of including the revisions in the working copies of those other users. Each user has the option to reject revisions published by other users so that the contents of each user's working copy of the database may or may not be maintained consistent with other working copies of the database operated on by other users. However, in order to ensure data integrity of the master database, each user that rejects the inclusion of revisions published by another user is prospectively prevented from publishing revisions to other users, until the user accepts the previously rejected published revisions. The invention employs a distributed architecture that allows each user to interact with that user's working copy of the database in a way that is controlled by that user without impairing the functionality of the database for other users. The database inconsistency allowed by the invention facilitates the performance by users of 'what-if' analyses.

Growing community of inventors

Sunnyvale, CA, United States of America

Michael J Deale