Before beginning any data migration, it is crucial to assess the volume of data to be transferred, including customer, partner, and prospect information. This assessment helps determine the complexity and resources required for the migration process, as well as any potential impacts on system performance and storage limits.
Additionally, understanding the data volume ensures that adequate preparations, such as data cleansing and mapping, can be completed prior to migration, which is key to a smooth and efficient transition.
For more on data migration considerations, refer to: Salesforce Data Migration Planning.