When Jacewicz & Son, in Bellows Falls, Vt., got started in the replacement contracting business more than 30 years ago, the company didn't need written job descriptions. Like so many other fledgling contracting firms, it was exactly what the name suggests: “primarily a family-run business with my father, myself, and a part-time secretary,” says president Jayson Dunbar.

But success meant growth, and growth meant hiring, and by the time the company had 15 or 20 employees, Dunbar realized he needed formal job descriptions. “We felt there was a need, primarily on the administrative end, for the initial hiring process, so people knew what was expected of them,” he explains.

GROWING PAINS Who wants job descriptions? Not most entrepreneurial home improvement contractors, whose first job description was simple: Do everything. But job descriptions can be essential in helping contractors ease the inevitable growing pains of a successful business, human resources professionals say.

Written job descriptions, “serve as a baseline for outlining minimum qualifications and expectations of duties to be performed,” says John Sweeney, human resources knowledge advisor with the Society for Human Resource Management, in Alexandria, Va. They also help to manage and evaluate performance and chart career paths in an organization by allowing managers to hold employees accountable. After all, how can you know if you're doing your job well if you're not sure what that job actually is? But job descriptions should not be cast in stone, Sweeney adds. Writing them is “a process, not an event.”

PERIODIC REASSESSMENT At Frey Construction & Home Improvement, in Prairie du Sac, Wis., owner Scot Frey and his managers, “reassess everything twice a year,” including the job descriptions they wrote jointly a few years ago, Frey says. “We're constantly fine-tuning to make sure everyone knows their job responsibilities.”

Contractors who make time for the process say it pays clear dividends. Not only do job descriptions spell out expectations for employees, they “take away the scare of not knowing how an employee will be replaced when or if they leave. So employees don't have as much leverage on us,” Frey says.

Adds Dunbar, “Having job descriptions makes hiring easier because you know what you're looking for. They also help gauge whether an employee is meeting his or her required duties,” he says. And for someone looking to move up in the company, Dunbar says, job descriptions act as a guidepost. “If they have access to a job description for another position, it tells them what to look forward to and what they'll be accountable for,” he says.