Hi 

You haven't described the business need in detail - maybe there is another way to meet it.

Perhaps a better idea than combining REPAIR and CRM is to use the production module in a natural way. You will define "product to be repaired" more easily, assign a BoM to it (consumables, operations to be done) and a PRODUCTION path (I don't remember - I think that's what they originally called in Odoo). 

The more you make an offer for this product, the MO (manufacture order) will be generated. 

Adding the appropriate rules will allow you to control the receipts of products for repair, the issuance of finished products and the recording of repair costs. Using BoM - will automatically account for the components used for repair (if they are entered there).