The purpose of this audit strategy is to set out the principles of how audit is managed in Crossrail. This document covers all Crossrail audits:  Crossrail Internal Audits; Crossrail Compliance Audits; Industry Partner Audits and Contractor Audits. It also covers all audit types; for example Quality; Environment; Health & Safety; Technical and Financial. It does does not cover commercial or cost assurance reviews of contractor activity.