The pervasiveness and growing complexity of software systems are challenging software engineering to design systems that can adapt their behavior to withstand unpredictable, uncertain, and continuously changing execution environments. Control theoretical adaptation mechanisms have received growing interest from the software engineering community in the last few years for their mathematical grounding, allowing formal guarantees on the behavior of the controlled systems. However, most of these mechanisms are tailored to specific applications and can hardly be generalized into broadly applicable software design and development processes. This article discusses a reference control design process, from goal identification to the verification and validation of the controlled system. A taxonomy of the main control strategies is introduced, analyzing their applicability to software adaptation for both functional and nonfunctional goals. A brief extract on how to deal with uncertainty complements the discussion. Finally, the article highlights a set of open challenges, both for the software engineering and the control theory research communities.

Verification of Graphical User Interface (GUI) applications presents many challenges. GUI applications are open systems that are driven by user events. Verification of such applications by means of model checking therefore requires a user model in order to close the state space. In addition, GUIs rely extensively on complex and inherently concurrent framework libraries such as AWT/Swing, for which the application code merely provides callbacks. Software model checking of GUI applications therefore needs abstractions of such frameworks that faithfully preserve application behavior. This paper presents JPF-AWT, an extension of the Java PathFinder software model checker, which addresses these challenges. JPF-AWT has been successfully applied to a GUI front end of a NASA ground data system.