A demonstration and discussion of the process and benefits of building a 'high level' strategic simulation tool for a UK Health Authority seeking to build an evidence base to support strategic investment decisions across the primary and secondary health care system.  The presentation will discuss the key drivers for change and performance expectations in the UK health system.  It will describe the rationale behind the Health Authority's request and the means of delivering on this.  Particular emphasis will be placed on the learning process that took place during model construction, the key links to strategic decision making, evidence of the benefits to the Authority during and since the simulator development and the way in which the simulator tool has been placed locally to inform and influence performance monitoring.  The workshop will demonstrate the model itself as well as outputs generated by at least one 'future scenarios' workshop held locally.