"We must have more leaders! We must have more leaders!" That's the great cry of management literature for the last twenty years. It's nonsense.
Pick up the dictionary and look up "leader." What will you find as a definition? It will probably be something like this: "leader: one who leads."
Note that we are talking about a leader as being defined by what they do. They're not defined by traits, or magic tricks, or what kind of shoes or watches they wear.
The fact is that everyone who is responsible for the performance of a group is a leader, because people follow the leader's example. That's what leaders do, they set the example and direction. If people follow you, then you're leading. You can lead well, or you can lead poorly, but you're leading.
The fact is, that if you take an individual who is responsible for a group, that person isn't a leader, or manager, or supervisor by virtue of some magic benefit that they got from the gene pool, or a magic set of tricks they learned at some seminar. All of those are roles, and you get to do every one of them if you're responsible for a group. Here are the differences between them.
Leadership, that's the one all the books talk about, is about purpose and direction and culture. Ultimately, the leader decides which direction the ship is going to go. When you're making those kinds of decisions when you're setting the example which defines culture, or when you're talking to people who work for you about why what they do is important, then you're doing leadership work; and, you're a leader.
But what if you're doing something else? Well, then you might not be filling the leadership role at that moment. Management is involved with groups and priorities. So, if the work you're doing at the moment is determining the vacation schedule, that's management work. It isn't any more or less noble than leadership work. Both of them have to be done, and done well.
And what about supervision? That's the forgotten function in most of those articles. Supervision is the part of your work where you deal with individuals and task performance.
If you're responsible for a group, you do all three of them, sometimes two or three at the same time. And none of those has priority all the time. The mix changes as you move up the organizational ladder, though.
If you're a first-line supervisor, you're going to do relatively more supervision and management and less leadership. It's the nature of the size group that you're responsible for.
Move up into middle management, and the management components get a little bigger so does the leadership component and the supervision component falls off a bit. But even if you're a top CEO in a top corporation, you still are going to be doing supervision, as well as leadership and management.
If you haven't read it (it's a great management book), pick up a copy of the book, "Execution: the Discipline of Getting Things Done," by Larry Bossidy and Ram Charan. Read about some of the things that Bossidy talks about doing with his direct reports. That's as much supervision as what any foreman does on the factory floor.
So, don't be misled by all the jargon and the hype. If you're responsible for a group, you've got to do leadership, you've got to do management, and you've got to do supervision. Don't worry about what you are, pay attention to what you're doing and what your group is doing, and you'll be on the road to success.