Since many workflow applications are used in contexts where the requirements and business rules change frequently, it is necessary to build those applications using strategies and tools that favor adaptation and reuse. The goal of this paper is to show an approach to build these extensible workflow applications using synchronized executable models. This approach uses concepts related to aspect-oriented software development, such as concern separation and instrumentation; thus, in addition to presenting the approach, we discuss our view on the central characteristics that define aspect-modeling, and we show how these concepts relate to our work and how they can be applied to workflow applications.