ABC Family just completed its most-viewed summer ever, with an average of nearly 1.5 million tuning into the network’s primetime offerings, and records set across all of its key young female demographics.

That’s no accident.

When Kate Juergens, executive VP of original series and development, joined the network in 2004, it was surviving on repeats of shows off of the WB: “Gilmore Girls,” “Smallville” and “7th Heaven.” Juergens was tasked with taking the network into original series.

Juergens dove headfirst into the research, and discovered that Millennials — kids who came of age around the turn of the century — have different values than the Gen X and Yers who came before them.

“Millennials embrace their families,” says Juergens. “They don’t see themselves as separate. Their parents are their best friends and they fully expect that to be true for the rest of their lives.”

ABC Family gained a little traction with its first original series, “Wildfire.” But it really got the ball rolling in July 2006 with “Kyle XY,” at the time the network’s best-ever premiere. “Kyle XY” reigned supreme until July 2008, when it was eclipsed by “The Secret Life of the American Teenager,” which bowed to nearly 3 million viewers. That show’s first season finale beat the CW’s “Gossip Girl” with nearly double the viewers at 4.5 million.

Since then, the network’s been on a constant roll. In summer 2009, it launched “Greek,” followed by last summer’s “Pretty Little Liars,” and “Melissa and Joey,” and this summer’s “Switched at Birth,” “The Nine Lives of Chloe King” and “The Lying Game.” By summer’s end, “Pretty Little Liars,” “The Secret Life of the American Teenager” and “Switched at Birth” were basic cable’s top-three scripted series among the network’s key demos of women 18-34 and females 12-34.

Juergens says her former boss, Paul Lee, who’s now ABC’s president of entertainment, always told her it took five years to establish a brand.

“He was right,” she says. “We started in 2004. Five years later, when we really started to feel comfortable with what we were doing and we really understood it, everything started to hit.”

Title: Exec VP, original series & development, ABC Family
Role model: Coco Chanel
Career mantra: “Play to your strengths!”
Leisure pursuits: “Traveling to new and unusual places. Hiking any of the many amazing L.A. trails. Yoga to clear my mind, and meals with friends of course!”
Philanthropic passions: The L.A. River restoration, Marine Conservancy.