Dynamic Aspect Oriented Programming (AOP) technologies typically provide coarse-grained mechanisms for adapting aspects that cross-cut a system deployment; i.e. whole aspect modules can be added and removed at runtime. However, in this paper we demonstrate that adaptation of the finer-grained elements of individual aspect modules is required in highly dynamic systems and applications. We present AspectOpenCOM, a principled, reflection-based component framework that provides a meta object protocol capable of ne-grained adaptation of deployed aspects. We then evaluate this solution by eliciting a set of requirements for dynamic fine-grained adaptation from a series of case studies, and illustrate how the framework successfully meets these criteria. We also investigate the performance gains of fine-grained adaptation versus a coarse-grained approach.