Taming software adaptability with architecture-centric framework

In many cases, we would like to enhance the pre-defined adaptability of a running application, for example, to enable it to cope with a strange environment. To make such kind of runtime modifications is a challenging task. In existing engineering practices, the online policy upgrade approach just focuses on the modification of adaptation decision logic and lacks system-level means to assess the validity of an upgrade. This paper proposes a framework for adaptive software that supports the online reconfiguration of each concern in the "sensing-decision-execution" adaptation loop. To achieve this goal, our framework supports an architecture style which encapsulates adaptation concerns as software architecture elements. And then, it maintains a runtime architecture model to enable the dynamic reconfiguration of those elements as well as help to ensure the validity of a change. A third party can selectively add, remove or replace part of this model to enhance the running application's adaptability. We validated this framework by two cases extracted from real life.