This module implements a shipping calculation very different from the widely used commerce_shipping module and is not compatible with commerce_shipping. This module is not as versatile as commerce_shipping and are specifically made to support the usecase where goods are shipped from different locations. The customer has no influence on how shipping is done.

With this module you can create a list of "shipping vendors" and attach these to individual products with an entity reference. The total shipping rate is the sum of vendors attached to products in the cart. This is usefull if the products are shipped from different locations each adding to the shipping cost. Each vendor is only added once no matter how many products use the vendor.

For each shipping vendor you can define a "base rate", "package size" and "package rate".
The cost for each vendor is base_rate + ceil( quantity / package size) * package rate. ( where quantity is the total quantity of products using this shipping vendor ). The base and package rate can be set to 0 and then have no effect.

The customer has no choices here, so there's no checkout steps related to shipping.

Installation :

Install and enable module as usual
Add entity reference field to your products, number of values should be set to 1 and target type limited to "Commerce vultivendor shipping"
Create some shipping vendors under "Store » Configuration » Multivendor shipping"
Assign the shipping vendors to the products

If you choose "Rendered entity" as the formatter for the entity reference it will show a text explaining the shipping costs for the current product and the shipping vendor description. The template for this text can be overridden in your theme.

Commerce Multivendor Shipping

Issues