Current approaches to modelling complex business processes fail to scale to large organizations. Key issues are cobweb and labyrinth problems exhibited by conventional box and line metaphors and large numbers of hidden dependencies introduced by compartment-based modularity. We have been developing a new approach, Enterprise Modelling Language, based on trees, overlays and fish-eye viewers to overcome these shortcomings of existing workflow notations. EML utilizes several visual metaphors to enhance the representation, navigation and management of large organizational hierarchies and process flows. We describe a prototype support tool, MaramaEML, that provides support for multiple visual notations including the Business Process Modelling Notation (BPMN), the EML tree-based, multi-layer hierarchical representation, fisheye zooming capabilities, automatic BPEL code generation, and inter-notation mapping. We describe our experiences using EML to model large business processes and initial evaluation results.