Tracking data lineage is as simple as indexing items with keys. This way, the data is tagged with an identifier that will follow it through every process. Examples of this type of identifying information include: names of authors, copyright, date of the original entry, or anyone who has accessed the data previously. Data lineage is of particular interest for business intelligence once project managers start investigating what input what into the final product. This information is valuable for the purpose of understanding how insights were formed, refining techniques or performing quality control on the data.