Non-conformance reports (NCRs) were a key part of Crossrail’s quality management system. They were used to record non-conformities (defects) in the works (product, workmanship, or electronic systems), and provided a disposition and documented information of the agreed resolution. NCRs could be initiated by any member of the project team, and were then investigated and resolved by the appropriate stakeholders.

This dataset provides a summary of all 25,232 NCRs raised within the Crossrail project in order to support lessons learned activities for other major construction projects.