Conceptual modelling has gained a lot of interest in recent years and simulation modellers are particularly interested in understanding the processes involved in arriving at a conceptual model. This paper contributes to this understanding by discussing the artifacts of conceptual modelling and two specific conceptual modelling processes: knowledge acquisition and model abstraction. Knowledge acquisition is the process of finding out about the problem situation and arriving at a system description. Model abstraction refers to the simplifications made in moving from a system description to a conceptual model. Soft Systems Methodology has tools that can help a modeller with knowledge acquisition and model abstraction. These tools are drawing rich pictures, undertaking analyses `one', `two', `three', and constructing a root definition and the corresponding purposeful activity model. The use of these tools is discussed with respect to a case study in health care.