Plains All American Pipeline LP (NYSE: PAA) and Plains GP Holdings (NYSE: PAGP) have provided details regarding its management succession plan and transition process on Nov. 7.

Plains’ CEO Greg Armstrong has informed the board of directors of his plans to retire at the end of 2018. Armstrong has been with PAA and its predecessor organizations since 1981. Armstrong will continue as non-executive chairman of the board of directors through December 2019, at which time he will retire from the board. Harry Pefanis will continue as president and a director.

Under the plan approved by Plains’ board, Willie Chiang, PAA’s current executive vice president and U.S. COO will become CEO upon Armstrong’s retirement. Chiang joined PAA in 2015 as PAA’s executive vice president and U.S. COO and was appointed to the board of directors in February 2017.

Chiang has more than 30 years of energy industry experience, having served in a number of executive leadership roles within large, complex organizations like PAA. Prior to joining PAA, Chiang has held positions at Occidental Petroleum Corp. (NYSE: OXY) and ConocoPhillips Co. (NYSE: COP).