Recovering Knowledge from Undocumented Legacy Systems

Legacy systems become a strategic risk when critical behavior is understood by only a few employees—or no one at all. The article proposes reconstructing system knowledge from the software itself by combining source files, database schemas, support history, test cases, and AI-assisted exploration of the live application. The resulting specification can expose dependencies, active functionality, and embedded business rules. Technology leaders should recover this knowledge before deciding whether to maintain, modernize, or migrate a legacy estate, reducing key-person and transformation risk.