We summarized some of the best practices and lessons learned during ERPNext data import efforts for our clients in the recent blog post: Learning from our Data Imports in ERPNext
Is this referring to one time import for migrating data from one system to another for live operation? Or some sort of on-going data transfer? Before or after going live? Also, what type of data/information are you importing? There are many different cases. If you are importing data that affect the accounting processes there are many considerations, like timing and what effect you are having on the GL, subledgers etc. That is the nature of a fully integrated ERP system which has accounting modules that you want to be/stay accurate.
@fblauer: thank you for the good questions. Actually the post covers our data import experience with data needed for operational management workflows
reference data (customers, customer groups, addresses, items, item groups, various CRM entities - contacts, leads etc.)
opening stocks per SKU items/Warehouses
opening balances on the bank accounts / cash desks etc.
(sometimes) historical data for transactions in past
HR module data
Etc.
In terms of data import affecting accounting registers (like GL, subledges etc.), we cannot agree more on sensitivity of errors there. we try to manage it in a way to have customers start a new quarter or fin year in a new system (thus only the opening balances per accounts of CA are imported to the system). This minimizes the room for errors there.
The manual talks about it here: https://frappe.github.io/erpnext/user/manual/en/accounts/opening-accounts
Cutting off at a year or quarter end is important, but there are still a lot of things to consider. especially if you are trying to do history, which I would avoid if possible. The manual talks about entering opening balances in the GL from the old system. Any temporary accounts which are used should be frozen after everything is balanced, so that people don’t use them after the conversion. (We just had that problem at a client)
For subledgers, the “opening entry” types should be used. The subledgers should be balanced to the control accounts in the GL. The manual also has a section on opening stock, and fixed assets.
Periods in the past should also be locked if they are finalized, so you don’t get transactions in there if they shouldn’t be. Those are some of the accounting controls to maintain integrity.