Method for Modification of Plan Appling TMS

Abstract

Most of the former planners can generate a valid set of operators under a static condition. But,once operational failure has occured in executing the operators, the only way to recover is the reconstruction of whole operators. So,if the difference between the new plan and the old one is smaller than the whole plan, a modification of the plan must become very efficient way. The system proposed in this paper can rebuild the plan as suitable for changed situation by deletion and assertion of operators considering their effect to the plan. Furthermore, this system can make the range of modification to minimum with hierarchical definition of operators. It consists of four major systems : Non-linear Planner which makes a valid network of operator for given problems, and TMS (Truth Maintenance System) which verifies consistency of the network, Node Creater which translates dependencies among factors of plan into data structure for TMS, and Organizer which manages other three systems and makes decision of a range and a method of modification.