RT Journal Article SR Electronic T1 How efficient can an emergency unit be? A perfect world model JF Emergency Medicine Journal JO Emerg Med J FD BMJ Publishing Group Ltd and the British Association for Accident & Emergency Medicine SP 972 OP 977 DO 10.1136/emermed-2011-200101 VO 29 IS 12 A1 Kesh Baboolal A1 Jeff D Griffiths A1 Vincent A Knight A1 Andrew V Nelson A1 Cheryl Voake A1 Janet E Williams YR 2012 UL http://emj.bmj.com/content/29/12/972.abstract AB Various approaches have been used to identify possible routes for improvement of patient flow within an emergency unit (EU). One such approach is to use simulation to create a ‘real world’ model of an EU and carry out various tests to gauge ways of improvement. This paper proposes a novel approach in which simulation is used to create a ‘perfect world model’. The EU at a major UK hospital is modelled not as it is, but as it could be. The ‘efficiency gap’ between the ‘perfect world’ and the ‘real world’ demonstrates how operational research can be used effectively to identify the location of bottlenecks in the current ‘whole hospital’ patient pathway and can be used in the planning and managing of hospital resources to ensure the most effective use of those resources.