How to add multiple production sub-processes
If you manage and track multiple production processes under one main process, you can easily manage and track them. All sub-processes can be listed under their respective parent process and can be selected when creating work orders.
To add sub-processes, go to Setup, then Tailoring Setup, and then Production Stages. Edit any production stage or add a new process.

Once you edit or add a process, you will be able to add subprocesses of that parent process.

To add subprocesses, enable the ‘Is sub-process allowed?’ option in the Sub-Processes tab. You can now add the required subprocesses. Enable if any subprocess is a default process, which means the subprocess will be auto-selected while creating work orders.
Add new by clicking the plus sign. Once done, click on Submit.