Some help with manufacturing process

Hello I need some help about how to use ERPNext. I appreciate your suggestions.

In the company I´m working we have the manufacturing process subcontracted. So our supplier manufactures some items with material that they purchase and material that we purchase, so I keep track either the supplier warehose or internal warehouse.

Normally, when we want to manufacture some items we generate a purchase order and our supplier starts to gather material with their suppliers.

The problem is that I don´t know how to carry out this process inside the erpnext. I don´t know if I must use the manufacturing part or Subcontracting.