This paper presents a Quick Scan diagnostic approach, developed to aid the understanding and documentation of a supply chain prior to the start of a major supply chain re-engineering change program. The Quick Scan aims to minimize the use of resources within the business being Quick Scanned while at the same time achieving maximum insight into logistics issues. A comparison of alternative diagnostics is presented along with a detailed explanation of the main process steps involved in the Quick Scan methodology. Three automotive case studies have been included to illustrate the benefits resulting from previous Quick Scans.