Data lineage

Data lineage describes the path a piece of data takes from its origin to its final use. For example: the sales figure in a report comes from the ERP, goes through a process that cleans it and converts it to euros, is aggregated in a data warehouse and ends up in a dashboard and a forecasting model.

It serves three very practical purposes: knowing who is affected by a change before making it; finding the source of an error when a number does not add up; and proving to an auditor or authority where the data in a regulatory report or AI model comes from.

The AI Act requires documenting the origin and preparation of training data for high-risk systems, and the GDPR requires knowing where personal data is: in both cases, lineage is the tool.