Case-based reasoning and real-time systems: Exploiting successfully poorer solutions

In the literature of real-time software applications, case-based reasoning (CBR) techniques have been successfully used in order to develop systems able to carry on with their temporal restrictions. This paper presents a mathematical technique for modelling the generation of solutions by a RealTime (RT) system employing a CBR that allows their response times to be bounded. Speaking in general, a system that tries to be adapted to highly dynamic environment needs an efficient integration of high-level processes (deliberative and time-costly, but close-fitting) within low-level (reactive, faster but poorer in quality) processes is necessary. The most relevant aspect of our current approach is that, unexpectedly, the performance of the system do not get worse any time that it retrieves worse cases in situations even when it has enough time to generate better solutions. We concentrate on formal aspects of the proposed integrated CBR-RT system without establishing which should be the most adequate procedure in a subsequent implementation stage. The advantage of the presented scheme is that it does not depend on neither the particular problem nor a concrete environment. It consists in a formal approach that only requires, on one hand, local information about the averaged-time spent by the system in obtaining a solution and, on the other hand, an estimation about their temporal restrictions.