Simulating the impact of policy on patrol policing: introducing the emergency service incident model David Carter a and Jonathan David Moizer b * Abstract Detailed processes for emergency response work and demand and resource management can be recognisably modelled using system dynamics. The Emergency Service Incident Model (ESIM) successfully joins together the very short timescales associated with providing an emergency service to the public, to the far longer periods involved in planning for the recruitment and training of police patrol officers within Devon and Cornwall Police. A system dynamics model is presented which can help inform decisions on patrol officer staffing requirements. The impact of a range of policies can be studied to determine new and better ways to resolve the supply–demand equation that delivers frontline policing services to the public. A number of alternative policy interventions directed at improving police patrol officer incident resolution are highlighted in this study and related scenarios are tested. Results show that particular attention should be directed towards better management of the backlog of routine incidents. Copyright © 2011 System Dynamics Society. Syst. Dyn. Rev. (2011) Introduction In Devon, Cornwall and the Isles of Scilly, policing activities involve travelling substantial distances. There are in excess of 60 police stations that serve a community covering sparsely populated moorlands, densely populated cities and where a quadrupling visitor population arrives each summer around the long coastline. Local emergency services have a history of innovation in overcoming the demographic and geographical challenges they face. The counties covered by the Force have neighbourhoods with some of the lowest crime rates across England and Wales, but also have some of the most deprived wards in the country. Devon and Cornwall Police (DCP) are facing the constant challenge of providing good policing to the community, which is resource efficient and provides value for money to the taxpayer. This paper uses system dynamics modelling to explore the dynamic tensions between providing a pipeline of experienced officers to the patrol–response function 1 and the demands placed on those officers to resolve incidents in a timely and professional way. Often the patrol officer provides the first response to calls for assistance from members of the public. Incidents are graded according to seriousness, and as a consequence of resource constrained conditions; the more routine incidents do not always get resolved within an ideal timeframe. a Devon and Cornwall Police—Middlemoor Headquarters, Exeter, Devon, EX2 7HQ, U.K. b Plymouth Business School, University of Plymouth, Drake Circus, Plymouth PL4 8AA, U.K. * Correspondence to: Jonathan David Moizer. E-mail: jmoizer@plymouth.ac.uk Received 6 July 2010; Accepted 20 April 2011 System Dynamics Review System Dynamics Review (2011) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/sdr.465 Copyright © 2011 System Dynamics Society