Which procedures do you recommend for concurrent engineering?

There are two approaches to manage file changes for teams working on assemblies. After users have completed their work on a specific subset of an assembly, they can do one of the following:

Perform Save and Unlock
When the entire assembly is saved to PLM, the integration displays the Take Ownership List dialog box. This dialog box shows the writable files, so the user can select those files that must be saved to PLM. The user should avoid selecting files that were not changed.
Perform Check In
After a file is checked in, you cannot change it until it is checked out (minor check-out in this case). Therefore, each time you check in a file, it is saved to PLM, and later changes are saved in a new version of the file.

For further information, see:

Saving and unlocking a file
Take ownership
Checking in a file