The process flow is as follows - 

Configurations

Since the process involves a multi-step process, we need to setup multiple products that represent the different stages of the product lifecycle. Apart from having the components (raw materials) and the finished product, we also need to have a semi-finished product because the product is essentially subcontracted twice. In this example, let us assume the raw material is a Blank T-shirt. After subcontractor A works on the black & white printing, let’s call it Semi-printed T-shirt. Finally, the finished product is called Graphic T-shirt. Lets take a look at how each of these products are configured in Odoo to ensure the correct route.

Firstly, make sure you have Subcontracting, Locations, Multi-step routes and Dropship turned on, without which we will not be able to configure these products.

Blank T-shirt

The Blank T-shirt will need to have “Dropship subcontractor on Order” set as the route, since it is being drop shipped from Vendor A to Subcontractor A.

To ensure that a PO is created for the right vendor, we also need to ensure that ‘Vendor A’ is set on the Purchase Tab.

Semi-Printed T-shirt

The semi-printed T-shirt will essentially be the finished product for subcontractor A. Since this product is then shipped to subcontractor B, we need to also set the route as “Dropship Subcontractor on Order”. 

However, on the purchase Tab, the Vendor will be set as Subcontractor A.

We also need to create a Bill of Material for this product since it is subcontracted. The BOM will need to be set to “Subcontracted” with the subcontractor being Subcontractor A. The component will be Blank T-shirt.

Graphic T-shirt

The Graphic T-shirt is the finished product that needs to be received by the user. This product needs to be set as “Buy” since we are simply buying it.

The Vendor will be set as Subcontractor B.

We will also need to setup a Bill of Material for the Graphic T-shirt since it is going through a second printing process with Subcontractor B. This time, the component will be semi-finished.

With this, all the product configurations and BOMs are setup to ensure that the user will only have to create a PO for the Graphic T-shirt. Let’s look at the process.

Process

1. Create a Purchase Order for Graphic T-shirt from Subcontractor B and confirm it. This will generate a receipt of the Graphic T-shirt.
2. This will trigger an RFQ for the Semi-printed T-shirt from Subcontractor A. The user will need to confirm this PO, which will generate a Dropship transfer.
3. A new RFQ will be generated for Vendor A for Blank T-shirt, which, upon confirming will generate a dropship to Subcontractor A.
4. The user processes the dropship of Blank T-shirt to subcontractor A and then processes the dropship from subcontractor A to subcontractor B.
5. Finally, the Graphic T-shirt is received from subcontractor B.

Points to note

1. By default, Odoo uses the generic “Physical Locations/Subcontracting Location” for both subcontractors. There’s nothing wrong with using this, but this means that both the dropship transfers will have the destination as the above-mentioned location, even though they are different vendors. It is recommended to create a separate subcontracting location for each subcontractor to ensure that you know exactly where the product is at any given point in time. To configure subcontracting locations, you can go into the subcontractor contact and view the Subcontractor Location field under the Sales/Purchase tab (ensure you are in debug mode).
2. If any of the above configurations are missed, the flow could break and hence with increasing number of subcontractors, you must ensure that both the product and BOM configurations are setup correctly.