Big Blue is planning one of its biggest restructurings in 15 years.

According to an internal memo sent to the hardware group on Thursday, the head of the division, William Zeitler, IBM wants to change its structure so that it is focused on the customer, rather than on a product line.

Zeitler claims that the the changes will mean that IBM can sell technology to small and medium-sized businesses and to design products specifically for them. The hardware-oriented management model makes it easier to sell to big corporations, but smaller companies often make the company more money.

IBM will create four client segments, including one governing hardware for large organizations and a separate one for small and mid-sized customers. The third segment will focus on "industry systems" in retail, telecommunications and health care, and the fourth on microelectronics, serving buyers of IBM's custom microprocessors.