During the design and development phase, you will need to work on data migration actively. The key steps during this phase include data mapping and transformation for the identified migration elements, creation of tests and a go-live plan for migration as well as developing the scripts, templates, and test datasets for migration.
Select source systems to use for migration. If the data is stored at multiple places in a legacy system, you should pick the cleanest one to extract a copy. Consider the update timings in the source and add dependencies in the go-live plan to get the source data updated prior to starting the extraction.
Define field mapping between the legacy systems and Dynamics AX, along with any transformations that need to happen between the extracts and the import processes.
Identify the areas that need data cleansing; have...