Design-to-time real-time scheduling is an approach to solving time-sensitive problems where multiple solution methods are available for many subproblems. The design-to-time approach involves designing a solution plan (i.e., an ordered schedule of solution methods) dynamically at runtime such that the solution plan uses the time available as productively as possible to try to maximize solution quality. The problem to be solved is modeled as a set of interrelated computational tasks, with alternative ways of accomplishing the overall task. There is not a single "right" answer, but a range of possible solution plans of different qualities, where the overall quality of a problem solution is a function of the quality of individual subtasks. The act of scheduling such pre-specified task structures that contain alternatives requires both deciding "what" to do and deciding "when" to do it. One major focus of our design-to-time work is on taking interactions among subproblems into account when building solution plans, both "hard" interactions that must be satisfied to find correct solutions (e.g., hard precedence constraints), and "soft" interactions that can improve (or hinder) performance. Another recent focus of our work has been on adding to the problem model the notion of uncertainty in the duration and quality of methods, and in the presence and power of soft interactions. Scheduling with uncertain information requires additions to the scheduling algorithm and the monitoring of method performance to allow dynamic reaction to unexpected situations.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-7514 |
| Date | 01 January 1996 |
| Creators | Garvey, Alan James |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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