The document discusses technical data migration and outlines key factors to consider when migrating data. It provides an example of migrating data from multiple sources like Access, network file servers, and ERP systems into a PLM system. It illustrates the different data streams involved like ECOs, BOMs, CAD files, documents and estimates timelines for migrating different data based on complexity. The document emphasizes understanding factors like required accuracy, transformations needed, and revision history to properly estimate a migration. The goal is to make technical data migrations easier to understand and explain to others.