Imagine spending an entire year coordinating a centuries-old, internationally broadcast event hosting world-renowned leaders, with more than 32,000 people in attendance. Now imagine that there’s no dress rehearsal.

For the past 20 years, working under the auspices of four Harvard presidents and two University marshals, Commencement Director Grace Scheibner has been responsible for the detailed planning and execution of the Harvard Commencement Morning Exercises, the largest event held on campus every year.

“I start the day after Commencement,” Scheibner said. “When you think of all the groups of people that have to come together — the degree candidates and their families, members of the administration, faculty, alumni, honorands, and special guests — it’s almost like a big movie set. Except here, there’s no rehearsal and no re-take. It has to be perfect, and it has to be flawlessly timed.  When it comes to logistics, there can be no ambiguities.”

Coordinating a complex event with such scope, detail, and history has seen Scheibner compared to both a military commander and director of a major motion picture. In 2010, the Commencement speaker, retired Supreme Court Justice David Souter, sent a letter to Scheibner after the event, saying he had recently been discussing the D-Day landing in France with a colleague. “I’m convinced you could have staged the invasion of France flawlessly,” Souter wrote.

“When you receive feedback like that, you know that you did your job, and that the year of hard work was worth it,” Scheibner said.

As Commencement director, Scheibner has been responsible for managing special requests from more than 200 honorands and 20 speakers, a task that has led to some last-minute scrambles.

“In 2004, two weeks before Commencement, I was told that our Commencement speaker required a private jet to fly him to Commencement,” Scheibner said, smiling. “How many people do you know who can immediately pick up a phone and hire a private jet? Everything else went on hold, and my entire attention became focused on the jet and added United Nations security. We were able to coordinate it, and everything was taken care of.”

Another time, just before Commencement began, one honorand realized that she had left her personal cap, which she wore whenever she processed at an academic institution, back in her Boston hotel room. “We were already lined up for the procession,” Scheibner said. “We dispatched the driver to the hotel, had the concierge let us into the room with the honorand’s permission, retrieved the cap, and raced back to Cambridge.  I walked to the rear of the platform just as the procession was coming up and handed the cap to the honorand as she took her seat.”

Despite such last-minute challenges, Scheibner says that her passion for the Commencement ceremony is a reflection of her own Commencement experience, when she graduated from the Harvard Extension School with an A.L.B. in psychology in 1990.

“I want to give back to Harvard what Harvard has given me in the way of an education,” Scheibner said. “At my Commencement, as people began to show up in their caps and gowns and we began to process, I saw the banners and the stage and was awestruck.  I didn’t know then that within two years I would return to Harvard and be offered the Commencement director position, one which I have taken very seriously ever since.”

Despite the presence of dignitaries, Scheibner said she never loses sight of who Commencement is really for: the degree candidates from the 13 undergraduate Houses and 12 graduate and professional Schools, and their families and loved ones.

“Something magical happens to this campus on Commencement morning. There’s an anticipation in the air. We bring the Harvard family together, under a beautiful canopy of trees and foliage, and everywhere you look you see magnificent crimson banners.  Graduating students and their families realize that this is the culmination of what they’ve been working toward for so long.

“I feel a deep commitment in making sure the Commencement ceremony is a lifelong, cherished memory for them,” Scheibner said.  “After all,” she added, “Harvard deserves the very best.”