CHESAPEAKE, Va. — In a reorganization of its senior management structure, Dollar Tree Inc. has promoted three ­executives. In addition, Duncan Mac Naughton, who had been serving as president of the Family Dollar segment of the business, has left the ­company.

The management changes are intended to improve the execution of Dollar Tree’s overall  strategy and improve the operational performance within both the Dollar Tree and Family Dollar segments.

“These and other actions we are taking are designed to increase enterprise-wide focus and accountability,” chief executive officer Gary Philbin said.

The organizational shuffle follows closely on the heels of the consolidation of the two banners’ support centers to the company’s corporate office located in Chesapeake, Va.

The promotions include the elevation of Michael Witynski to the post of enterprise president of Dollar Tree Inc., with responsibility for merchandising, store operations and supply chain functions at both Dollar Tree and Family Dollar.

Witynski most recently had served as president and chief operating officer of Dollar Tree Stores since 2017, after holding the office of chief operating officer from 2015 to 2017. From 2010 to 2015, he was senior vice president of stores.

Prior to joining Dollar Tree, Witynski served as president of Shaw’s Supermarkets, part of Albertsons Inc.

In his new role, Witynski’s main focus is on enhancing enterprise-wide operational efficiency and lowering distribution costs in both retail segments. He continues to report to Philbin.

“Mike Witynski has been a key executive in driving performance across the organization,” Philbin said. “In particular, Mike has led the store excellence operational initiatives and merchandising programs to drive sales and margin, and has been hands-on in managing our tariff mitigation efforts the past 18 months. His promotion to enterprise president will continue our progression of elevating our customer-facing efforts in merchandising and ­operations.”

Also moving up is Richard McNeely, who has been named chief merchandising officer, with oversight of merchandising, marketing and global sourcing for both business segments. He is primarily tasked with improving merchandise gross margins while also upgrading value for the customer. He reports to Witynski.

McNeely had been chief merchandising officer for Dollar Tree Stores since 2017, after serving as senior vice president of merchandising from 2008 to 2017. Before joining Dollar Tree, he held positions of increasing responsibility in merchandising, marketing, global sourcing and store operations with a number of retailers, including Dollar General Corp., Roses Discount Stores and Fred’s Inc.

In addition, Thomas O’Boyle Jr. has been promoted to COO, leading store operations and real estate functions for both Dollar Tree and Family Dollar. Among his responsibilities are optimizing the real estate process, improving the customer experience and addressing recent problems related to inventory shrink. O’Boyle also reports to Witynski.