The advice I've offered in these columns so far has been directed to entrepreneurs who are already established.

But what if you're starting a business? Let's say that you have a great idea and either have the financial backing to launch or know where you can get it.

Or perhaps you're already in business--and now you see an opportunity to take your operation to a much higher level, perhaps via geographic expansion.

There is much to consider, and it's shocking that one of the most important factors is rarely discussed in advice forums. It's this: The effect your decision will have on your family and friends. Make no mistake: They will pay a price for your decision to start or grow your business.

You can forget about work-life balance; it doesn't exist for successful entrepreneurs. Starting a business or significantly expanding one is never a 40-hour or even a 60-hour-per-week job. The attempt places huge demands on your time and energy--so much so that, to your family and friends, it might seem that you literally disappear. Small wonder that marriages and other important relationships often are strained or broken after entrepreneurs immerse themselves in their business enterprises.

So, answer this question: Should you proceed--or back away?

Your family will share in your success, of course--and not just monetarily. Watching (and perhaps even participating) in the Herculean challenge of starting and growing a company offers everyone (including young children) life lessons that can't be learned elsewhere. Going through the storms of business-building can reveal much about the depth of your relationships--and about your own abilities. But success often is modest; those who achieve "rich and famous" are rare indeed.

That makes it even more vital that you weigh the potential for divorce or long-term damage to your children. Will your venture be worth it?

To lessen these risks, have a frank discussion with everyone close to you about the stresses that your new operation might create--for you as well as for them. If you don't make it a family decision, your odds of success--defined as happiness, not merely hitting certain financial targets--are sharply reduced.

When my wife, Jean, and I started our business nearly three decades ago, we did so together. Win or lose, success or failure, we knew that we would share the results and that the experience would make our union stronger. Before we quit our jobs and launched our business, we made sure we understood the demands it would place on our time, energy and modest financial resources. Then we committed to it and never looked back. We know our success could never have happened if we hadn't made the decision together.

I contrast this with a newspaper account I read recently about an entrepreneur who started his firm without his wife's support. His marriage suffered, and his children resented his absences. Though the marriage survived, he said that if he could turn back the clock he wouldn't do it again.

It's great to have an entrepreneurial spirit, but before you take on a new venture, make it a family affair. Be sure to consider all of the costs--not just the economic ones.