In today's workplace, the promotion of one person to a supervisory slot in charge of fellow co-workers is common. It signals a change in the workplace. For the co-workers and their new boss, things will not be the same.

"You are not one among us, you are one above us," said Donna Flagg, principal of The Krysalis Group, a business and management consulting firm in New York City.

The situation has pitfalls for bosses and workers.

"Every time you pick a new leader, there was someone who wasn't chosen," said Ed Ryterband, a corporate psychologist and managing director at RHR International in New York City. "It is a very, very significant issue that gets very little attention."

Much depends on how a company handles the transition, said Ryterband.

Fifty percent of people who are newly hired to an executive position leave in the first 18 months, he said. "Part of that is the way they are hired and integrated is haphazard," he said.

It can start before the promotion is made. A good process will let promotion candidates know where they stand before the decision is made, said Karl Gordinier, a retired vice president of human resources at International Flavors & Fragrances Inc. who now owns a consulting firm called Gordinier Resource Management.

Once the decision is made, the best way to avoid the potential problems is communication.

"It is very important for the hiring manager to sit down with the person or people who are not chosen and say, 'This is where we are going and this is why and do you have any questions about that,' " Ryterband said.

Discussion topics can include the new boss' role in the team and where they will be headed in the future.

"The new manager has to make every effort to begin establishing new relationships that have different dynamics than they did as peers," Flagg said. "You can't ignore that there is a shift in power."

Accordingly, Remi Pauwels realized that the relationship would change when he joined friend and former co-worker Frankie Francese at a new job with a recruiting firm, where Francese would be Pauwels' boss.

Francese, 34, of Howell, N.J., said he wanted to be clear that he wanted to maintain a friendship but his role in the organization, as a boss, was different. The working relationship had to be the priority, he said. He told him that he wouldn't be able to treat Pauwels differently than other employees.

"At times, I might even be harder on him just to show the others that I wasn't favoring him," he said. "The first few weeks, first couple of months, we locked horns a little bit. We were open and honest with each other. We discussed our differences and we both needed to adapt."

Pauwels, for his part, realized that his friend had an office to run and had to make budgets and quotas. "I would answer the challenge and do whatever I needed to do," said Pauwels, 31, of Wall, N.J.

It worked out. The two men remained friends and are now partners in their own company, Fortis Consulting Group LLC., a recruiting firm.