A business wants to change systems and discovers that its export contains customers but no links to orders or files. Data portability is easier to plan while the application is being designed.
Identify the information the business owns
List the record types, stable references, relationships and attachments that need an export route. Include definitions or lookup values needed to interpret the fields.
Decide who may export information and how private files are protected. A convenient export feature should not expose more records than the user's role permits.
Test a small round trip
Export synthetic related records and check that another person can understand the package. Open attachments, inspect identifiers and compare important values. A file existing on disk is not enough.
Document limitations, provider dependencies and any specialist extraction work outside the ordinary feature. Keep the export format versioned if it may change.
Bring ownership and handover expectations into the project agreement. Source access, data access and ongoing hosting are related but separate matters. Clear arrangements give the business a practical route to maintain, extend or move its software later.
Test long references and leading zeros in the exported package. Opening a file in a spreadsheet can change numeric-looking identifiers and make later record matching harder.