This pattern of networked organizations involved in production has in many instances replaced the more hierarchical vertically integrated organizations of the 20th century. One of the reasons for increased contracting and production networks is the increased specialization required in production. As technology advances and customer demands increase, organizational expertise becomes more narrow and focused. A key management decision in many organizations is what we call the "make or buy decision": When making that decision management poses a simple, but profound question: Is this work central to who we are as an organization and therefore we must "make" this part of our product, or should we buy it from an outside vendor? For example, at Columbia University Barnes and Nobel runs the bookstore. Columbia does many things well, but running a bookstore isn't one of those things and so the university contracts it out to a bookstore company. Apple computer designs its products in California, but for the most part manufactures its products in Asia. For Apple, design, not manufacturing, is their core competence.