Solution : https://service.sap.com/sap/support/notes/440648 (SAP Service marketplace login required)
Key words : 
display dialog box 'copy standard text', additional key words co796, ocm-relevant material, product cost collector, read master data, attached program corrections, problems occur, planned orders, transactions co40, production orders
Related Notes : 
       
| 454636 | CO40: Routing is exploded repeatedly | 
| 391846 | Modif: Reading master data when converting planned order | 
| 391678 | No homogeneity list after conversion of planned order |