It's like the part was written by three writers locked in separate rooms.

"Tommy Boy" stars Chris Farley of "Saturday Night Live," the guy with the size 23 neck, as Tommy Callahan, the dopey son of a Sandusky brake shoe manufacturer. His father, Big Tom (Brian Dennehy), is proud of him even though he squeaked through college in seven years, and supplies him with an office and big responsibilities when he comes back to Ohio. Meanwhile, there are startling developments on the domestic front, where Big Tom, a widower, is engaged to marry the bodacious Beverly (Bo Derek).

Young Tommy is overjoyed, because Beverly has a son, Paul (Rob Lowe), which means Tommy at last will have the brother he always dreamed of. Paul doubts there's much to do in Sandusky, but Tommy proves him wrong, introducing him to the favorite local pastime, "cow tipping," which means sneaking up on sleeping cows and tipping them over. In other hands this could have been the movie's only funny scene, but director Peter Segal doesn't have a clue about comic payoffs and bungles it before ending with the desperate director's ancient standby, as the lads fall in the mud.

The plot thickens. Or does it congeal? I began ticking off the story clichés: We'd already had (1) dumb son returns to family business and (2) unexpected stepmother. Soon we get (3) company gets in trouble and all workers will lose jobs, (4) it's up to the kid to save the day, (5) evil stepmother, (6) road movie and (7) buddy picture. The last two come as Tommy hits the road in a desperate last-minute bid to sell brake shoes, accompanied by his friend Richard (David Spade, also from "Saturday Night Live"). Richard has been introduced as a resentful employee who doesn't think Tommy should get such a quick promotion. Now he becomes a sidekick, critic, rival and buddy, all wrapped in one ungainly package.