Hi,
I have worked on an implementation where the customer was upgraded from AX 2009 to Dynamics 365. There are two parts for the upgrade:
- Code
- Data
For the coding part, you need to review if all customizations are still required or probably replaced with standard features. E.g. my customer was having customizations to send items to POS and websites and importing sales orders in return. This has been replaced with standard retail features. Also another way of working on several departments did reduce the need for customizations. Be aware that it is not possible to do overlayering anymore, so all customizations should be written as extension.
Related to the data part, Microsoft does provide a tool which makes it possible to map AX2009 data to Dynamics 365. Then it can be exported as CSV files and imported as master, reference data and journals for open balances.
In my case, the tool was not available at that time. Then we did create Excel files using ODBC queries on the AX2009 database. These Excel files were refresh-able, so master data could be cleaned up in AX2009 first. The column definitions were aligned with the data entity columns for Dynamics 365, so it was also very convenient for import using data management in Dynamics 365.
