One of the realities of performing well in your current position is that you will likely be rewarded with a promotion. When taking on these new roles, be cognizant of the Davies’ Doctrine, which is the concept of getting promoted to and leading beyond your “Level of Current Competence.” This is analogous to, but more optimistic than, Peter’s Principle (which focuses on reaching a level of incompetence).
From the Davies’ Doctrine viewpoint, it is not accurate to believe you will be totally incompetent for any position to which you are promoted, but you will likely develop partial areas of incompetence that need to be overcome.
In academia, for example, being promoted to department chair may include responsibilities, such as the budget, for which you are not trained. You can overcome this by either negotiating for a business manager who has the fiscal training or by acquiring the skills yourself, perhaps through an MBA program or accounting classes.
View this brief infographic to help see how you can excel in your new role (view a printable version of the infographic).