When planning and advancing core system replacement, EDI is often overlooked even though it becomes a major obstacle. EDI systems have typically been built with different specifications for each trading partner, so they cannot be migrated to a new system as-is in many cases, and as a result, rebuilding becomes unavoidable. However, the high complexity and effort required for rebuilding can become a drag on the entire project, and this is a major reason why EDI is often left out of core system modernization. ■ Why different EDI specifications make rebuilding unavoidable The need to rebuild EDI stems from customized specifications optimized for each counterparty. Communication procedures, data formats, code systems, and business logic have each been built independently and are tightly coupled. In addition, decades of operation often lead to dependency on individuals and black-boxing, making it difficult to accurately understand even the current specifications in many cases. For this reason, a simple migration tied to core-system replacement is not realistic, and projects end up requiring redesign and reimplementation—rebuilding. ■ Approach to implement EDI rebuilding smoothly This webinar explains practical approaches to minimize burden and execute smoothly, starting from the premise that rebuilding cannot be avoided. By leveraging an EDI library (template-based specifications), there is no need to develop each transaction pattern from scratch, significantly improving rebuilding efficiency. In addition, by using development tools to standardize and automate data conversion and integration workflows, it becomes possible to rebuild while reducing effort, schedule risk, and project risk. For situations where "rebuilding is unavoidable," we will share key points and practical answers on how to do it successfully and realistically. ■ Organizer / Co-host Userack System Co., Ltd. ■ Cooperation Open Source Utilization Research Institute Co., Ltd. Maji Semi Co., Ltd. Maji Semi