In what ways did IBM’s corporate-level strategy help protect and defend its business-level strategy?

From its beginnings as a company that developed instruments to measure time, IBM grew to become the world’s largest computer company. At its height in 1966, its stock was valued at $140; in 1993, its stock was trading at $42 a share, and shareholders had lost hundreds of billions of dollars of their investments. How could a giant company like IBM have fallen so low? How could the company strengths that contributed to its success have led to its fall? Why did IBM lose control of its customers and markets? To understand the problems that IBM currently faces, we need to look at IBM’s past and at the way its strategy and structure developed over time.