Apple said Monday that John Ternus will become the company’s next chief executive officer on Sept. 1, while Tim Cook will assume the role of executive chairman of Apple’s board of directors, according to an official company announcement.

The iPhone maker said Cook will remain CEO through the summer and work closely with Ternus to ensure a smooth transition. The change was approved unanimously by Apple’s board and follows what the company described as a long-term succession planning process.

Ternus currently serves as Apple’s senior vice president of Hardware Engineering. Apple said he has spent 25 years at the company and will also join its board of directors effective Sept. 1.

The move marks Apple’s first CEO transition since 2011, when Cook succeeded co-founder Steve Jobs.

Apple also said Arthur Levinson, who has served as non-executive chairman for the past 15 years, will become lead independent director on Sept. 1.

In a separate announcement, Apple said Johny Srouji was named chief hardware officer effective immediately, taking over the hardware organization previously overseen by Ternus.