SUMMARY: A data portability drill tests whether a platform export can preserve useful continuity outside the service that created it.
The presence of an export button is not proof of portability. An archive can be technically complete and operationally useless: opaque identifiers without documentation, conversations separated from attachments, timestamps stripped of time zones, or structured records flattened into files that cannot be imported anywhere else.
Portability is discovered after the download. The question is not only whether data can leave, but whether meaning, relationships, and practical control survive the trip.
Choose a Bounded System
Select one service with moderate importance and a manageable record set. Request the standard export without using administrator-only tools. Record how long delivery takes, which identity checks are required, and whether the request itself changes account access.
Test Five Layers
Completeness: compare the export with a sample of visible records, deleted items, settings, and attachments.
Structure: verify that relationships between people, messages, projects, and files remain machine-readable.
Interpretability: check whether formats, field names, identifiers, and time values are documented well enough for another tool to understand.
Reusability: import a small portion into a neutral tool or a replacement service and measure what must be repaired manually.
Independence: confirm that the archive can be opened after logout and does not rely on expiring platform URLs.
Record the Exit Debt
List every missing field, broken relationship, proprietary format, and manual repair step. Assign an owner and a review date. If the system is critical, preserve recurring exports before an emergency makes the first test unavoidable.
This drill turns the exit cost ledger into evidence. It also extends the evidence exit route by testing whether exported records remain usable rather than merely available.
Operator rule: data is portable only when another system can recover its meaning without permission from the system being left.