Abstract
This research deals with reconfigurable uniprocessor embedded real-time systems to be implemented by different OS tasks that should be independent, synchronous, and periodic, and that should meet functional and temporal properties described in user requirements. The authors define two forms of automatic reconfigurations assumed to be applied at run-time: addition-removal of tasks or just modifications of their temporal parameters; WCET and/or periods. The authors define a new semantic of reconfigurations where a crucial criterion to consider is the automatic improvement of the system's feasibility at run-time.