Our customer (a FMCG manufacturer) is using Tally for accounting purpose currently, and is willing to integrate ERPNext (to automate accounting of Sales,Manufacturing, procurement etc.,). We are evaluating between the following approaches .
Keep ERPNext as the master accounting system, and replace Tally going forward. We are not sure if there are any delta functionalities of Tally, that ERPNext cannot support.
Keep Tally as the master accounting system, but feed the accounting data from ERPNext platform realtime (through Tally API calls).
Not sure on what basis should we decide one of the above two approaches. Are there any other suggestions. Customer does not have any preference yet, and are open to our suggestions.