typically 3 production batches [Note for Guidance on Process Validation - European ...]

http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2009/09/WC500002913.pdf

Dear Rishabh,

Data on 1-2 production scale batches may suffice where these are supported by pilot scale batches, and by a history of consistent manufacture of products by essentially equivalent processes.

For more details, please see the following link:

http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2009/09/WC500002913.pdf

Hoping this will be helpful,

Rafik

Perhaps of some interest for your query:

https://www.researchgate.net/post/how_to_explain_the_difference_between_simulation_and_experiment_result