It can be said with some level of assurance that few expected this program to become the first primetime animated hit in 25 years and the first genuine series breakout in the history of Fox Broadcasting; one spun, no less, from a ratings flop called "The Tracey Ullman Show."

"I don’t think you can anticipate a cultural phenomenon, but once the series premiered we knew we were on to something really special," says Sandy Grushow, chairman of the Fox Entertainment Group. "There was little doubt that once this thing hit it would immediately change the face of television."

Now the longest-running animated series ever to grace any size screen, "The Simpsons" sprints into its second decade (and 11th season) with an eye on immortality. Comparing this show with TV’s previous traditional long-running sitcoms, "The Simpsons" now trails only "The Adventures of Ozzie & Harriet" (14 seasons); the combo of "All in the Family"-"Archie Bunker’s Place" and "The Danny Thomas Show" (13 seasons apiece); and the 12-season runs of both "My Three Sons" and "The Lucy Show"-"Here’s Lucy" run.

Come spring, "The Simpsons" will reside --- in terms of sheer seasonal longevity --- astride the formidable likes of "Cheers," "MASH," "Happy Days," "The Jeffersons," and, uh, "Married with Children," all of which completed 11 seasons. As it is already committed to a 12th season and likely a 13th, "The Simpsons" is certain to crack the all-time sitcom top five before it’s done eviscerating sacred cows and disemboweling popular culture.

Aye carumba, indeed.

Mind you, this sort of unprecedented durability and continuity has been realized by "The Simpsons" despite an ever-evolving cast of characters pushing the buttons (and envelopes) behind the scenes. Enduring the transitions between four day-to-day executive producer regimes and perpetual turnover amongst the writing staff has proved to be the show’s biggest challenge and blessing.

Blessing? Oh yes, explains "Simpsons" co-developer and exec producer James L. Brooks, whose company Gracie Films has supplied a guiding hand in producing the show from its inception.

"What’s kept this show going strong is the energy and the freshness and the vitality that each succeeding executive producer has brought to it," Brooks contends. "David Mirkin didn’t have to follow the same path, or produce the exact same kind of comedy, as Al Jean and Mike Reiss did. And Mike Scully has brought it his own unique signature.

"The guys guiding the show have a certain carte blanche to make it broader, more character-based, more satirical or whatever. They know they can take ‘The Simpsons’ to different places as long as they do it really well."

That sort of eclecticism has been essential to reinvigorating "The Simpsons" every few years and preventing staleness from setting in on a show that, by all rights, should have been reduced by now to a mere shadow of its once-uncompromisingly clever self. The fact that it’s still firing bulls-eyes well past the 200-episode mark is a testament to the writers, Brooks adds.

"We have enough veterans on the writing staff who stick around and keep the new kids on track," Brooks says. "And even the old hands come back a few times every season to lend a hand. No one ever really leaves ‘The Simpsons.’ It’s bizarre. But it fuels this kind of wonderful continuity."

It is part of series TV legend that "The Simpsons" drives its writing staff to go where no scribes have gone before in terms of dedication to the task at hand. Scripts have been known to undergo upwards of 20 revisions and are tweaked, updated and polished literally up until the week of airing.

A lesser man than Scully would be whipped into an angst-riddled stupor by a painstaking process so dense with topical satire. But Scully, who has been a writer and producer on "The Simpsons" since April 1993 and its primary exec producer the past two years, nonetheless calls the Matt Groening-created series "a writer’s paradise."

"This show is an amazingly collaborative effort on the part of everyone in every department," Scully says. "But if you ask me how ‘The Simpsons’ is able to tick on and on and on, I would put it simply like this: ‘We all have bills to pay, OK?’"

Scully is serious when he admits that his primary goal was pretty much not to break anything when he took over the show as exec producer.

"The pressure comes in suddenly having this legacy to live up to," Scully notes. "Nobody wants to be part of the team that sank ‘The Simpsons,’ and fear is a great motivator. That’s truly how we all approach it now."

Not wrecking the series creatively proves to be an increasingly daunting mission with each passing season.

"We’ve definitely more than hit the point where sitcoms pull these desperation moves to spawn fresh storylines," Scully acknowledges, "like adding a baby or an alien neighbor or something. It’s hard not to stoop to that."

Maybe too hard. Scully points out that later in this 11th season, "The Simpsons" will suffer the death of a major character. Marge? Homer? Bart? No ... not Maggie!

"Bear in mind," assures Scully, "that there are about 60 regular characters on this show. It makes it really easy to screw with people’s heads on a regular basis."

There have been few major production crises in "Simpsons" history. But one occurred back in 1998 when the show’s primary voices (including Dan Castellanata, Julie Kavner, Nancy Cartwright, Yeardley Smith, Hank Azaria, and Harry Shearer) put up a united front during contract negotiations and nearly forced the series to bring in temporary replacements.

No animosity has lingered between the voice talent and their fellow "Simpsons" staffers, assures Cartwright, the voice of Bart Simpson from the get-go.

"This does happen to be the best job on the planet," Cartwright says, adding, "I think even Fox would acknowledge that they can’t really afford to pay us what we deserve considering what we’ve meant to the show. That’s what the dispute was all about. But it’s behind us now, until the next negotiation, that is."

Contract squabbles or no, "The Simpsons" looks remarkably fit for a show that will soon turn 77 years old in dog years. Somehow, this series is spending its Geritol-and-shuffleboard years pulling off a remarkable impersonation of a hungry young buck.

It comes as no surprise to Brooks.

"All of us know there will never be anything in our lives like ‘The Simpsons’ again," Brooks says. "This to me is the thing that is always going to happen to other people, that lightning you capture in a bottle. And it shows what you can do when great instincts and great passion collide."

Transcribed by Jeff Fiedler.