This is Glenn Perry's method.
As a predictive tool, the Developmental Age Method (DAM) is different from transits, progressions, or solar returns. Rather than tracking the actual or symbolic movement of planets in relation to natal positions, it sees each natal planet as itself symbolizing a specific period of the life. This allows for the interpretation of a natal planet in terms of its sign, house, and aspects, but also with respect to the developmental stage in which it occurs. In so doing, it adds an additional dimension of meaning to any planetary configuration. For one can now discern that planet’s impact not only for the year it signifies, but also in the context of the overall life cycle. Notable events of that planetary year may have diachronistic reverberations in subsequent stages associated with the planets it aspects.
More information can be found on the Astrolabe website here: Developmental Age Method (pdf)
