When testing data transferred between systems, what is usually important?

The most effective approach when testing data transferred between systems involves testing both before and after the transfer. This comprehensive strategy ensures data integrity and validates that the transfer process has succeeded without error.

Testing before the transfer allows for establishing a baseline of the data, where you can confirm that it is complete, accurate, and in the expected format. This step is crucial for identifying any issues that may exist before the transfer takes place, thereby preventing any erroneous data from moving to the new system.

Testing after the transfer serves to verify that the data has been accurately transferred and remains intact. This involves checking that all data fields are populated correctly, that there has been no corruption during the transfer, and that the data adheres to any necessary constraints or requirements in the new system.

By performing both pre-transfer and post-transfer tests, any discrepancies can be effectively identified and managed, leading to a more reliable and trustworthy data migration process.