LHCb Computing Model

This document outlines the LHCb Offline Computing model, with emphasis on the resource requirements for the computing centres and the infrastructure needs. The document has a dual purpose: to motivate the LHCb computing needs, and to provide guidance to the management of the computing centres on the fabric needs of LHCb. The roles of CERN (Tier-0), the Tier-1s and the Tier-2s are discussed. It is expected that this will be a living document and will be revised as circumstances dictate and further information becomes available. The period covered by this document is from 2006 to 2010 with emphasis on the first full year of data taking (assumed to be 2008) and the subsequent two years.