The maintenance activity remains a delicate and expensive operation for any kind of applications. The aim of this paper is to present a reengineering approach that is especially suited to multitasking applications. In this context, a framework for the maintenance of this kind of applications has been integrated into the LACATRE graphical software development environment.The framework is based on a three steps approach. In the reverse engineering step, a source code is mapped into a graphical view composed of the low-level objets and actions, close to those supported by various executives. Then, in the design recovery step, this low-level view is transformed into a high-level one, using applicative objects. On both levels of abstraction, quality improvement can be performed. Finally, the high-level constructs are intended to be reused, e.g. in future designs.