pre-production 
noun [mass noun]
Work done on a product, especially a film or broadcast programme, before full-scale production begins: [as modifier]: the pre-production script...
- You get to see production every step of the way, from story sessions to pre-production to filming to the post-production.
- Plenty of detail on every aspect of the film from pre-production to opening night is covered.
- Sadly for them, this film was ‘too late’ by the time it began pre-production in Italy.