My company crusher machine manufacturing. so manufacturing process are 6 step. few step processing for another company(subcontracting) and return my company go for another process to finished. so my question this process how to apply for subcontracting in erpnext.

One machine add and put step by step operation mention. but my problem first 2 operation my company and middle operation for subcontracting company and again anothe 2 process in my comany and go for finished item. how to achive middle subcontracting operation in ERPNEXT.