Information System Engineering has made the assumption that an Information System is supposed to capture some excerpt of the real world history and hence has concentrated on modelling. Very little attention has been paid to the conceptual modeling process. However the emphasis on system modelling is shifting to process modeling. The particular Requirements Engineering (RE) process modelling approach being presented in this paper advocates the capture of the history of RE artifacts. In this paper, we present an approach for defining a way of working providing guidelines for the development of information systems. This way of working is defined as an instance of the NATURE meta-model. Therefore, it consists in the execution of different types of related contexts, namely, a choice based context, followed by some plan or executive based contexts, depending on the decisions made. We propose to view the process of modelling domain knowledge as a decision based process, as suggested by the process theory developed at the University of Paris Sorbonne.