Safe Substitution of Components in Self-Adaptive Web Applications

Open systems such as Web applications are dynamically adaptive to allow desired levels of flexibility. The adaptibity may be achieved by replacing constituent software components at runtime, and a new method is required to ensure that the replacement or substitution is safe. This paper proposes a formal framework of safe substitution for self-adaptive systems and presents a policy-based, system integrity verification method. In an example case, an adaptive Web application demonstrates the effectiveness of the proposed approach.