Boy this is a strange one: Samsung recently announced that two of its presidents will assume co-CEO roles with current CEO Kwon Oh-hyun. Three CEOs. Since CEO stands for Chief Executive Officer, having three CEOs in one company is a little oxymoronic. I am a big believer in the need for having a single person responsible for the performance of an organization. Why? In practice, it is really difficult for the multiple CEO concept to work effectively. I understand why people feel like two or three heads must be better than one and that better decisions will result. I think those benefits can be obtained without the disadvantages of the multi-CEO structure by copying a practice from the military.
For example, in the U.S. Navy every commanding officer of a ship also has an executive officer who reports directly to him. All of the department heads report through the executive officer. This provides a training position for future commanding officers in addition to providing someone for the commanding officer to bounce ideas off of without compromising the chain of command. This can be accomplished in larger companies by putting a president in place between the CEO and the rest of the functional leaders. This way you gain the value of having multiple heads on a problem without clouding the question of who is responsible at the end of the day.
Samsung Tests Whether Three Heads Are Better than One (Harvard Business Review)