Process-sensitive embedded user assistance aims to provide the end-user the necessary guidance based on the state of the process that is being followed. Unfortunately, the development of these systems is not trivial and has to meet several challenges. The main difficulties appear to be related to integration of process-sensitive guidance in the application and the crosscutting behavior of help concerns. To address these issues we developed an aspect-oriented tool framework Assistant-Pro that can be used to develop process-sensitive embedded user assistance for multiple applications. The framework provides tools for defining the process model, defining guidance related to process steps, and modularizing and weaving help concerns in the target application for which user guidance needs to be provided. The framework has been developed and validated in the context of Aselsan, a large Turkish defense electronics company. © 2011 Springer-Verlag Berlin Heidelberg.