Planning supply chains is a problem involving different paths, products and their quantities, storage costs, transport costs, and initial product costs. It also needs to take into acount transport and storage limits as well as final demand.
There were three different versions, in the first one the objective was just transporting the products the cheapest way possible. In the second one the planner needs to first choose where to buy the products then transport them.
Finally, in the last version the planner could choose where to buy inputs, which factory to send them, transform them into something else and send the final product to a final customer.