Timeliness in auto-adaptive distributed systems

Designers of auto-adaptive systems must devise a way to engage the right response at the right time. In order to bring auto-adaptive capabilities to mainstream distributed systems, it must be ascertained that the adaptation architecture is capable of mounting appropriate adaptive responses in a timely manner. We present an approach to designing adaptation control frameworks that facilitate such time-appropriate adaptations. We have used this approach in designing various adaptation control architectures using the QuO (quality objects) adaptive middleware framework.