In the years since he strutted onto the scene — lean, handsome, mouth running a mile a minute — in Doug Liman’s “Swingers” (1996), Vince Vaughn has become one of the poster boys for the mainstream American comedy: from romantic (“The Break-Up”) to bromantic (“Old School”), pretty good (“Wedding Crashers”) to very bad (“Fred Claus”) to frankly unnecessary (“Delivery Man”).

His new film, “Unfinished Business,” falls into that last sub-category — perhaps not coincidentally, as it, too, has been directed by Ken Scott (“Delivery Man” was Scott’s remake of his own homegrown Quebecois hit, “Starbuck”). A guys-gone-wild romp in the well-worn tradition of Todd Phillips’ “Hangover” franchise, this is the latest example of a movie that doesn’t work hard enough to freshen up formulas used and abused by filmmakers like Phillips, Judd Apatow, Nicholas Stoller (“Neighbors”), Seth Gordon (“Horrible Bosses”) and others.

Indeed, “Unfinished Business” will seem woefully familiar to most anyone who’s been to a movie theater — or taken a long plane ride — over the past 10 years. Male sexual panic gags involving penises? Check. Drug-fueled bacchanals shown in slow-mo? Check. Car hijinks (here involving a German-language GPS)? Check. Disposable, misogynistically conceived female characters? Check. Lessons learned (don’t be a bully; never give up; appreciate what you have)? Check.

And check, please.

Vaughn plays Dan, a St. Louis sales exec who quits his job toiling for a bullying boss named Chuck (Sienna Miller, gamely overdoing a brassy American accent) and starts his own company with two fellow workplace outcasts: retirement-age Timothy (Tom Wilkinson) and sweet-natured but slow-witted Mike (Dave Franco, you-know-who’s little brother). The unlikely trio travels first to Maine, then to Europe in an effort to beat out Chuck for a lucrative deal with a firm fronted by Jim Spinch (James Marsden, smarming it up).

Needless to say chaos ensues. But “Unfinished Business” never works up enough momentum to get us into the anarchic spirit of things. The movie unfolds, choppily, as a series of half-hearted set pieces written and directed with little flair or commitment and no connective tissue between them; some of those sequences scarcely run long enough to register, as if the studio couldn’t decide whether or not they were worth keeping in the final cut.

When it’s not indulging in lowbrow sex humor (not a bad thing in itself, mind you), the script, courtesy of Steven Conrad (“The Pursuit of Happyness”), tosses around some very lame jokes — sometimes repeatedly. Much is made, for instance, of the fact that a main character’s last name is Pancake; are you laughing yet? Even one of the movie’s more gently amusing bits, Mike’s serial mispronunciation of words like “exploit” and “imperative,” is run into the ground.

There are a couple of good lines strewn here and there — Dan references Walt Whitman’s “Song of Myself” while telling his overweight son (Britton Sear) that masturbation is OK — but most of the dialogue is in-one-ear-out-the-other forgettable.

Vaughn’s work here might be best described as functional — he does a very slight variation on the same persona he’s been playing for years: the brash guy with a heart of gold. As appealing and assured a comic performer as he is, the actor hasn’t stretched or challenged himself in a long time; “Unfinished Business” makes one hope, more urgently than ever, that he has something else up his sleeve on the next season of “True Detective.”

If the movie has a bright spot, it’s Franco. Speaking in stoner-surfer cadences, his face regularly expanding into an infectiously goofy grin, the actor is the one person onscreen who seems determined to cobble together what little he’s given into a distinctive character.