After resisting them for most of my career, I’ve changed my feelings about job descriptions. I think they are useful. Useful, but sometimes dangerous.

Job descriptions are dangerous because of their tendency to limit an employee’s work, responsibility, and — most important of all — his imagination. In an environment where job descriptions are revered, all sorts of work can fall through the cracks, ignored for years like a leaky pipe, and cause unnoticed damage, waste valuable resources, etc.

The extreme version of this is illustrated by union shops. And if you’ve ever been involved in putting on a seminar in any big city, you know what I’m talking about. In setting up the A/V system, you discover that at least three or four separate specialists are needed to get your equipment going. One guy can push in the audio plug but not the video hookup. Someone else is in charge of switching on the electricity. Don’t try to talk one tradesman into doing the work of another. And don’t you dare do it yourself. It’s not only enormously expensive to work this way, it’s amazingly inefficient.

But, as I said, this is an extreme case — an example of job descriptions gone wild. And it clearly makes no sense.

What does make sense?

I used to think it was a good idea to simply give new employees a general description of their responsibilities, outline my expectations for them, and explain my conception of how the job fit into the overall scheme of things. “But don’t think that’s all you’re going to do,” I would caution them. “If I think the job requires something else, you’ll do that too.” And then I’d sit back and see how well they handled it.

I’ve changed my mind about this process just recently, having been unexpectedly thrown into a supervisory role for a multi-million-dollar real estate development program that I had, until then, tinkered with from afar. At a distance, the arrangement of responsibilities didn’t matter to me. There was a single person reporting to a board of directors and, as a member of that board, I paid attention only to what she said.

When problems with the project spurred me to get more closely involved, I discovered that we were asking one executive to do the job of three, and so I hired two more people and divvied up responsibilities. Because the positions were new (and to keep them from stepping on one another’s toes), we all discussed what I needed each one of them to do. Then, to make sure there were no misunderstandings, I asked them to write single-page descriptions of what they were going to do, how they were going to do it, and how they saw their jobs in terms of the overall project.

I was surprised at some of what was returned to me.

There were, to say the least, a significant number of overlapping issues, contradictory viewpoints, and some very wrong-headed ideas about the overall purpose of the project. These problems were cleaned up pretty quickly with a series of phone calls and e-mails. Still, I could not help thinking about what chaos would have ensued had I not asked for the job descriptions.

As we went on to further refine the overall master plan, hiring some new people and firing others, the one-page job description became a useful way to:

* identify the number and degree of responsibilities

* agree on the priorities

* discover and resolve areas of conflict

* correct dangerous misconceptions

* establish specific goals

* set timelines

The trick to making job descriptions work is to:

1. Have a pretty good idea of what the job entails before you do the hiring.

2. Discuss the job responsibilities with your newly hired employee and define specific goals for his first three months, for six months, and for one year.

3. To make sure he is clear on what he’ll be doing, ask him to write a one-page job description for himself, using short sentences and bulleted phrases.

4. Correct any misconceptions immediately.

And one other thing: Everyone should know that in a growing company responsibilities change as opportunities arise. A typical job description, in my view, will be changed — at least in some minor way — every three or four months. So use job descriptions to agree on the parameters and get the communication straight, but don’t use them as a way to fossilize your business.