Have you ever wondered why the promotion you recently made just isn't working out? He or she was our best millwright or engineer but they are really struggling as managers. They seem to be able to handle the technical tasks but the morale on the floor is dropping.
Did you ever think that the skills that made them successful in their previous roles are not going to help them in their new one? They were good at dealing with machine issues as the machines were somewhat predictable and then you put them in charge of the most unpredictable of all machines - human beings!
Set your people up for success by choosing those who will grow into the leadership role and ensure they get the support as they move on to a completely different set of skill set requirements.