Who actually produces a part, service, assembly or any other input needed by the supply chain ? How do traditional organizations do this ?

Who actually produces a part, service, assembly or any other input needed by the supply chain ? How do traditional organizations do this ? Why is this decision different if we take a supply chain view of the world ? Building on the case The case dealt with a make buy decision driven by price As the articles make clear these decisions are often driven by much more than the price Outsourcing HR? How about design?