Some of the oldest organizations usually make a distinction between the range and the position. For example:

In the Catholic Church, it is one thing to be a bishop / cardinal; the other bishop /archbishop. In the Armed Forces, it is one thing to be a captain / major / colonel; another is to be a company commander / battalion / regiment. In the University, it is one thing to be associate professor / holder; it is another thing to be a teacher of the course X, or be a director or dean. The distinction is maintained despite the fact that tend to be more or less close relations between the two echelons (the archbishop of Santiago will tend to be chosen a cardinal at some point, in principle should be in command of a company should be a captain).

And the distinction is not only a way to offer ‘honors’ in two ways. In fact, both echelons have rights and duties distinct. In the Church, the Pope is chosen by cardinals (a distinction of rank), not by the archbishops (a distinction of position). And so we could look for other examples.

Now, what is it that earns an organization with a dual career ladder? It is true that at least earn the chance of promotion, and promotion that lead to specific benefits, without the need to change positions. But that is true of any organization, and not all of them make that distinction.

One can develop several ideas, but none seem to be too good:

• What a hold-over of personal items, individual bureaucratic organisations? The position -the archbishop of Santiago, the director of the department of Sociology, commander of the III Division of the Army – is fully bureaucratic; but the range remains a personal recognition, a personal right. The post may be a charge, but you are personally, and take it where ever thou goest, your range.
• Does the flexibility that provides a career ladder is not competitive? There can be only one archbishop of Santiago, but the church as a chilean, in principle, could have several cardinals. Then, if there are multiple people with the requirements to use the range X, I’m not limited by the organizational structure. In that sense, allows the ‘race officials’ do not stop even when, for various reasons, there are not too many changes in positions per se.
• What a way to achieve equivalence in organizations highly complex and differentiated? The hierarchical structures can be very different in various parts of the organization, with various levels, relationship between them etc, The system of ranges allows you to make equivalent positions are very different. And without the need of making the equivalence of strict and formalized (the cardinals are all in the same place, although in a given moment the positions occupied by the cardinals in your set are not the positions that they occupy in the other).
• Does the form in which it affects the processes of promotions? Suppose that for a given position requires a certain rank. Then, to occupy the position X can only be those who have the rank A. By a party limits the universe (not all can occupy it) and on the other hand, extends (all the range they can take, not only those who have occupied this position).

Whatever the reason, and I doubt that those mentioned are in fact the most relevant, it seems to me an interesting phenomenon to analyze and, at least, to note.