We need conceptual modelling languages to gain domain knowledge in the requirements engineering and analysis phases of an IS development project. These languages should serve an IS expert as means of communication between him or her and the domain expert. Many different modelling languages have been used for conceptual modelling. Consequently, questions relating to the quality of these languages have arisen. Wand, Weber and others have evaluated these languages using an ontology. Each of the languages was found to contain certain deficits. Because our aim is to construct a language without such deficits, we propose the opposite technique. We develop an ontologically clear modelling language for process modelling with the help of the BWW representational model. In addition to this modelling language, we introduce a process model which guides model creation. Both components form a conceptual modelling method.