In this paper we outline the design, development and application of a hospital patient flow management support tool – Hospital Event Simulation Model: Arrivals to Discharge (HESMAD). The model captures the patterns of patient flows within Flinders Medical Centre, a teaching hospital located in South Australia, through extensive exploitation of an existing hospital patient journey database (PJD). HESMAD employs mathematical and statistical modelling techniques, as well as the concept of modular design, to construct functions and processes that are embedded in a discrete event simulation system. The current structure of HESMAD reflects many iterations of refinements based on feedback from relevant industry experts. It places great emphasis on providing an engaging visualisation of the dynamics of events, and a convenient interface for domain experts: doctors, hospital managers and other health care professionals. An illustrative example of HESMAD's wider applicability is presented.