he ability to modify an existing plan to make it conform to the t f constraints of a new (or changed) planning situation is importan or plan reuse, replanning and case-based planning. While , [ significant amount of past work addressed this problem (e.g. 2, 3] [5, 1] [13] [17], [16]), there is still a lack of understanding . F of the general types of modification strategies and their coverage o...

The problem of minimally modifying a plan in response to changes in the specification of the planning problem has already been investigated in the literature. In this paper we consider the problem of non-minimal modification of plans from a computational point of view. We prove that while the general problem is intractable (that is, replanning from scratch is equally hard), there are scenarios ...

We present a theory of plan modification applicable to hierarchical no&ear planning. Our theory utilizes the validation structure of the stored plans to yield a flexible and conservative plan modification framework The validation structure, which constitutes a hierarchical explanation of correctness of the plan with respect to the planner’s own knowledge of the domain, is annotated on the plan ...

The ability of a planner to modify a plan is considered as a valuable tool for improving ee-ciency of planning by avoiding the repetition of the same planning eeort. From a computational complexity point of view, however, it is by no means obvious that modifying a plan is com-putationally as easy as planning from scratch if the modiication has to follow the principle of \conservatism," i.e., to...

We explore phase transitions of plan modification, which mainly focus on the conformant planning problems. By analyzing features of plan modification in conformant planning problems, quantitative results are obtained. If the number of operators is less than ub  , almost all conformant planning problems can’t be solved with plan modification. If the number of operators is more than lb  , almos...

Effective mapping and retrieval are important issues in successful deployment of plan reuse strategies. In this paper we present a domain independent strategy for ranking a set of plausible reuse candidates in the order of cost of modifying them to solve a new planning problem. The cost of modification is estimated by measuring the amount of disturbance caused to the validation structure of a r...

the main objective of the current study is to investigate the impacts of environmental evolutionsat global scale on iran’s environmental planning. thereby, all political movements towards solving environmental issues in iran were accurately reviewed to find out the impressibility of the events by the global environmental evolutions. the findings indicated that iran has joined the conventions an...