According to the stage approach companies start selling products in their home markets and then they sequentially enter other markets

According to the stage approach companies start selling products in their home markets and then they sequentially enter other markets. Two main stage approach models can be identified: the Product Life Cycle Theory by Raymond Vernon (1966; 1971; 1979) and the Uppsala Internationalization Model (Johanson & Vahlne, 1977, 1990, 2006; Johanson & Wiedersheim-Paul, 1975).
According to Vernon (1966; 1971) the internationalization process of the firm follows the development of the product Life Cycle. In particular, during the 60s Vernon observed that products in their introduction phase were initially produced in the U.S. (the home market) and exported to other countries. When the products went through their maturity phase, production was started in other advanced countries, serving local markets. Finally when the products became standardized production facilities were open also in less developed countries to meet local demand. More specifically, Vernon identified three stages: