Plant engineering is carried out in planning, engineering, procurement, construction, operation & maintenance (O&M) processes. A large number of deliverables are generated at each stage. These deliverables are submitted as as-built deliverables during the transition from Engineering, Procurement and Construction (EPC) stage to O&M stage. Once the as-built deliverables are verified, they are handed(turned) over to the O&M phase. South Korea is one of the first countries that managed the configuration of its nuclear power plants. However, an issue has been raised with the possibility of data loss, resulting from the lack of data interconnectivity in the information system for configuration management. In order to address this issue, it is necessary to trace the configuration information between varied as-built deliverables. In this study, we reviewed the traceability to improve the safety and reliability for the O&M of nuclear power plants. In particular, we propose a new process that improves the traceability between as-built drawings, the most important part of as-built deliverables, through a practical example.