Apple on Thursday said that Bob Mansfield, Apple’s senior vice president of Hardware Engineering, will retire and the role will be transitioned to Dan Riccio, Apple’s vice president of iPad Hardware Engineering, over several months. The entire hardware engineering team will continue to report to Mansfield until his departure.

“Bob has been an instrumental part of our executive team, leading the hardware engineering organization and overseeing the team that has delivered dozens of breakthrough products over the years,” said Tim Cook, Apple’s CEO. “We are very sad to have him leave and hope he enjoys every day of his retirement.”

“Dan has been one of Bob’s key lieutenants for a very long time and is very well respected within Apple and by the industry,” added Cook. “Our hardware engineering team is the best engineering team on earth and will not miss a beat during the transition.”

As senior vice president of Hardware Engineering, Mansfield has led Mac hardware engineering since 2005, iPhone and iPod hardware engineering since 2010, and iPad hardware engineering since its inception. Mansfield joined Apple in 1999 when Apple acquired Raycer Graphics, where he was vice president of Engineering. Mansfield earned a BSEE degree from the University of Texas at Austin in 1982.

Riccio currently serves as vice president of iPad Hardware Engineering and has been instrumental in all of Apple’s iPad products since the first generation iPad. Riccio joined Apple in 1998 as vice president of Product Design and has been a key contributor to most of Apple’s hardware over his career. Dan earned a bachelor’s degree in Mechanical Engineering from the University of Massachusetts Amherst in 1986.