The lean production system (a vertical complementary strategic alliance) pioneered by Toyota and others has been diffused throughout the global auto industry. In vertical complementary strategic alliances , such as the one between Toyota and its suppliers , the strategic center firm is obvious , as is the structure that firm establishes. However , the same is not always true with horizontal complementary strategic alliances where firms try to create value in the same part of the value chain For example , airline alliances are commonly formed to create value in the marketing and sales primary activity segment of the value chain.