how to configure co-pack of a manufactured item

We will be entering into our first "co-pack" partnership and need to configure it in JDE World Software.  The co-pack partnership provides us control over the quantity and specification of the raw materials that we will provide.  We will be purchasing raw materials and they will be shipped to our co-pack partner.  The co-pack partner will provide other raw materials and assemble the final product and ship it to us.

We see this process as our inventory at the co-packer, issues to a work order and completion of the assembled product.  Our analysis is to create a separate branch plant and have inventory transactions.  We would set up a Bill of Material at the co-pack Branch-Plant and use it for Standard costing, it would consist of the materials we supply and one purchased item for both the materials the co-pack supplies and the assembly.  We do not see a use for a router.  Our work order would be the order placed with the co-packer.  Their invoice to us would trigger