What is Vertical disintegration ?

Is the market large enough for the company to buy input effectively? Maybe better to specialize and buy inputs from the “front” suppliers. Conversely (Chen (2005)). Whether a company can produce its own input also depends on the horizontal competition in the downstream stage. If the competitors are also going to buy inputs the vertically integrated company can realize economies of scale in the production of inputs  cost savings by increasing size. Consider for example the automotive industry. For example, Porsche, which outsourced the 1990s large parts of processes to subcontractors. Approximately 80% of Porches added value created today by subcontractors. Another example is the Iphone: Naturally, an American product? Much of the production of components takes place in China.