Abstract: The increasing transparency and accountability of all organisations , including public service and government, together with the modern complexity, penetration and importance of ITC (information and communications technology), for even very small organisations nowadays, has tended to heighten demand for process improvement everywhere. This means that Business Process Modelling is arguably more widely relevant than say Time and Motion Study or Total Quality Management (to name two earlier efficiency methodologies) were in times gone by. Put simply Business Process modelling aims to improve business performance by optimising the efficiency of connecting activities in the provision of a product or service. Business Process Modelling techniques are concerned with mapping and workflow to enable understanding, analysis and positive change. Diagrams - essentially flow diagrams - are a central feature of the methodology.