The University of Sussex

Goal feasibility assessment: architecture, representation and control strategy

Remedios de Dios Bulos

This paper posits the idea of goal feasibility assessment, a reasoning mechanism that is intended to give the agent the consciousness to decide early and rationally on the fate of its goals. It may be described as a reasoning process for evaluating whether an agent's detected goal is possible (or doable) and rational (practical) to achieve. The doability of a goal is evaluated based on the capability and knowledge of the agent to pursue the goal as well as the satisfaction of resource and situational constraints pertinent to the achievement of the goal. On the other hand, the rationality of pursuing a goal is assessed based on the net total benefit (or net utility value) attributed to the agent and its environment when a goal is successfully achieved. In addressing the issue of goal feasibility assessment, this paper seeks to determine the nature and representation of knowledge that the agent requires in assessing the feasibility of its goals. It also aims to define a control strategy for goal feasibility assessment and provide a supporting architecture. In brief, goal feasibility assessment shall be addressed through architecture, representation and control strategy. The system architecture consists of a knowledge base and seven processors, namely: urgency evaluator, planner, plan searcher I, plan searcher II, hard constraints satisfier, utility assessor and best plan selector. The knowledge base contains the nature and structure of knowledge that the agent requires for assessing the feasibility of a goal. This includes the detected goals, causal rules, existing plan library, current beliefs, built-in operators library and active plan options. The goal feasibility assessment control algorithm consists of three stages. Plan generation/search and urgency evaluation are processed in the first stage; hard constraints satisfaction and computation of expected utility value for each alternative plan are undertaken during the second stage; and selection of the best plan for the goal is done in the third stage.

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