A real-time system is adaptive if it is able to adjust its internal strategies in response to a change in the environment, to keep the system performance at a desired level. In adaptive real-time systems, resource needs of applications are usually highly data dependent and vary over time. In this context, it is more important to obtain systems, which can very well adapt their execution to the changing environment than to apply the too pessimistic hard real-time techniques.
Aiming at meeting worst case demands results in extremely costly over dimensioning of resources. Rather, schemes should aim at providing efficient resource usage and acceptable user perceived quality.