Apple named its first chief operating officer in four years as part of a broader management shuffle Thursday, bestowing the job CEO Tim Cook last held under Apple's iconic founder Steve Jobs to a company veteran.

Jeff Williams, who joined the company in 1998, has overseen the company's supply chain, its service and support functions, and has played key roles with both the iPhone and the Apple Watch, the company said. "Jeff is hands-down the best operations executive I’ve ever worked with," Cook said in a statement.

As part of the announcement, Apple shuffled a few other management roles, naming marketing head Phil Schiller to oversee the company's App Store, and Johny Srouji, who leads Apple's semiconductor team, as a senior vice president leading hardware technologies. The company also said it hired Tor Myhren from the ad agency Grey New York to helm its advertising campaigns.

But it is the naming of Williams as operating chief that's likely to get the most attention. After all, Cook built his reputation as Jobs's behind-the-scenes supply chain and operations whiz. A savvy and demanding operator whose disciplined approach to management made him the operations yin to Jobs's creative yang, Cook earned his current title doing the same job.

Yet a report in the Wall Street Journal, citing an unnamed senior executive, said the move wasn't necessarily a signal that Williams was the likely successor to Cook, who has only been CEO since 2011 and, at 55, is hardly near retirement age. Rather it makes official a role Williams had already been playing at Apple. "As we come to the end of the year, we’re recognizing the contributions already being made by two key executives," Cook said in the statement.

That's unlikely to stop some outsiders from speculating about whether this could mark the anointing of an heir apparent, said Peter Crist, chairman of the executive search firm Crist Kolder Associates. "It's a common reaction or response when a COO is named," Crist said, "and at times it's inappropriate." 

He thinks this is one of those times. As Cook takes on an increasingly external role -- speaking out frequently on social issues like equality -- it makes sense to put someone else in charge of operations, Crist said. That allows Cook to focus even more on strategy, new product development and being the face of the company. "The pressure now on the CEO for external activities is just incredible," he said. "And if they adopt a mission mind-set, like Apple has, that really takes a lot of time." 

Meanwhile Apple is facing questions about its growth in iPhone sales, with several analysts trimming their estimates for the number of iPhone shipments for 2016. Colin Gillis, director of research for BGC Partners, agrees that formalizing Williams's operating role could give Cook more freedom to focus on growing the company's services business.

"I hope it does," he said. "Apple needs to focus in on reducing its dependency on iPhone hardware sales and building up more of a subscription and recurring revenue stream." 

While Apple is adding a COO, more companies have been leaving the slot open. According to numbers compiled by Crist's firm, roughly 33 percent of companies in the S&P 500 have a chief operating officer, down from 48 percent in 2000.

"Companies tend to use this COO role with an accordion mind-set," he said. "The role closes or opens based on the need you have at the company."

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