But many tasks that typically fall to a managing director are now done by one of the city's deputy mayors, who report to both Barnett and Mayor Nutter.
For example, last year, when the city managed a massive parade in honor of the World Series-winning Phillies, the deputy mayor for transportation and public utilities, Rina Cutler, took media questions on the post-parade cleanup.
During the controversial attempt last fall to close city libraries, the deputy mayor for health and opportunity, Don Schwartz, was front and center.
And currently, the deputy mayor for public safety, Everett Gillison, is in charge of preparation for a potential city workers strike.
"By charter the managing director is really the chief operating officer of the city, but that's been less and less the case," said Zack Stalberg, chief executive officer of the Committee of Seventy, a political-watchdog group.
"It seems as if Dr. Barnett is not really playing that role. Whether it's the mayor's choice or her choice, she seems to take on these singular projects."
Barnett said she supports the setup, which gives more authority to the deputy mayors, noting that it is a common governing structure in other cities.
"I think one of the things this organization does is strengthen the executive function," Barnett said. "I'm a supporter of the deputy-mayor concept."
Asked if she thought the responsibilities awarded the deputy mayors diminished her role in the government, Barnett said: "I don't view power as a zero-sum game."
Nutter agreed that he had organized his government to spread some of those responsibilities around, but stressed that this system meant that Barnett could focus more time on government reform.
