Adaptable objects for dependability

Abstract

Computer applications are meant to satisfy functional and non functional constraints derived from their design specifications. Nevertheless, in current highly dynamic execution environments, unpredictability of execution contexts makes it difficult to ensure that during execution some system properties such as times of response, precision, security and so for, will behave as expected. This uncertainty affects system dependability negatively. Static approaches are effective if all events affecting the system can be predicted or bounded, which is not the case for most of current systems. For more general cases, our approach is to provide dynamic adaptability capabilities to applications in order for them to deal themselves with unexpected situations. Indeed, we bring these capabilities as close as possible to where real action takes place, that means, at object level in object oriented systems. Being provided with adaptation capabilities and guided by appropriate decision criteria, our objects adapt their behavior dynamically in function of their execution contexts, improving in this way system dependability. © Springer-Verlag Berlin Heidelberg 2003.