JK Shin, co-CEO of Samsung Electronics and mobile division chief, is stepping down from hands-on management of the smartphone business, Reuters reports. Although Shin will remain in technical charge of the overall mobile division, his role as president will be taken over by Dongjin Koh, who will handle day-to-day operations. Shin will focus on new businesses and long-term strategy.

Koh was head of Samsung's mobile R&D until now, reportedly "playing a key role" in the development of recent Samsung phones like the Galaxy Note 5 and Galaxy S6. Both phones were well-received critically, representing a shift toward premium design for Samsung, but the flagship S6 only managed to make a "quite marginal" impact on Samsung's earnings earlier this year and subsequently underwent price cuts.

As you can see from the chart above, Samsung's mobile profits have been in decline for years, although the company did record a slight profit growth last quarter. Koh's task is easy to explain but will be difficult to pull off: Samsung Mobile must defend itself from assaults on all sides.

Apple has been increasingly dominant in the high-end smartphone market, especially since releasing larger-screened iPhones, while cheaper options from the likes of Xiaomi are getting more and more competitive. What Samsung needs is genuine product differentiation; the company may have decided that Koh is its best bet.