Pat, 36 and Jody, 35, are siblings employed in their family's $5 million company, Mayday Ambulance Service, Inc. Both have brand-name MBAs, and they entered the business at about the same time.

They are both capable leaders and have achieved significant success in their own divisions of the company. Their styles are different, however. Pat is more introverted, a planner, and strong on detail and follow-through. Jody is more extroverted and creative and possesses excellent interpersonal skills.

Though they have different personal interests and travel in different circles, they have always been fairly competitive with each other.

Their dad, Malcolm, 59, founder and president of Mayday, wants to address succession issues. The future of ownership is perfectly clear to him. "Ultimately, Jody and Pat will each own 50 percent of the common and voting stock," he says.

When it comes to leadership succession, however, Malcolm is stumped. "Every so often, I consider the notion of co-leadership, and I wonder if it might work. I've done a lot of reading about family-business issues and want to avoid a stalemate, but both of my children are capable leaders. I think they ought to decide for themselves who should run the company."

And, of course, Pat and Jody think Dad ought to be the decision maker. So what is Mayday to do?

BMC's Response: Take a Test Drive

A co-leadership arrangement can work, but it can also lead to conflict. Rather than Dad or the children guessing about whether it will work, Pat and Jody should take a road test.

The siblings can engage in a rigorous process directed by a neutral third party, and at the end, either they will have the confidence that they can forge a strong partnership or they'll know that working as co-leaders isn't for them.

The road test consists of creating a "partnership charter." This is a written document that goes well beyond the legal and financial concerns of the usual shareholder or partnership agreement and beyond the obvious issues of decision making, compensation, perks, and resolving impasses. It deals with the sensitive issues, such as bringing in additional partners or family members, measuring and rewarding performance, comparing levels of ambition and commitment, discovering what each brings to the business and takes out of it, and determine what feels fair.

As part of the process, they would examine their personal styles and values to see how these mesh and include what they would be willing to do to enhance their working relationship.

Creating a charter also involves extensive scenario planning. A mediator or trusted adviser gets the siblings to negotiate their way through myriad "what ifs"--for example, what if the company's fortunes nose-dived and capital infusions were required.

If they learn that they can negotiate with each other and complete a charter, they'll deserve their father's--and each other's--trust and confidence. The process of working on a charter removes the guesswork. And if they can do it, they'll have an invaluable map to guide them into the future.