Transits have many uses and have the advantage of being very concrete. By concrete I mean that the planet is there in the heavens influencing your planets in a visibly obvious way. Compare that to Dasas where you have to wonder why the Dasa work they way that they do! The truth is that transits, when used completely, are more accurate than Dasas. Dasas are very simple; in a few minutes based on the position of the Moon an astrologer can calculate the Dasas for the entire life of a person. Because of their simplicity, they are a little vague at times, still worth using, but difficult to catch EVERY event. Calculating transits completely for a person for just one year will take many, many times longer. Dasas have the advantage of being easy to calculate and in a medieval time without computers, it is easy to see how they gained prominence in timing events. And Dasas can be great, however, Transits work better – IF they are done completely and to do that is an amazing amount of work. How much work? To give you an idea, it takes my computer 4 seconds to calculate transits for one year for one Bhava! But that technique will give much, much better results than will Dasas.
There are basically five ways in which transits may be used: Gocara from the Moon, Ashtakavarga, as Event Triggers, to make Perfect Predictions, and for Mundane (world event) Astrology.
The most basic method of using transits is to consider the Gocara (transit) from the position of the natal Moon. This gives a simple understanding of the ups and downs a person will be experiencing with their lives. It shows how motivated they are to get behind different things in their life at different times. Since motivation is, to a great degree, a reflection of what is happening in our lives, Gocara from the Moon is a useful, though simple, tool for predicting the ups and downs in life.
Ashtakavarga is a more evolved system of using transits and includes within it all of Gocara from the Moon. Ashtakavarga has the advantage, however, of showing not only how the individual will get behind the different things in t heir lives, but how everything else also supports or burdens everything else in their lives. It is much more accurate than using Gocara from the Moon by itself and reveals a much better profile of the ups and downs in a person’s live based on all the factors in their lives, not just the self-created ups and downs. Gocara from the Moon shows what the individual is doing to create their circumstances; therefore, it is important to always consider Gocara from the Moon as a priority part of Ashtakavarga. Ashtakavarga can also be used for determining favorable times to perform an action, for timing windows during which specific events may occur, for determining things such as the direction one will find their spouse, how a person should set their house up, how many children they may have, etc. It is really a complete system that goes beyond transits.
One of my favorite ways to use transits is as Event Triggers to time an event foreseen with the Dasas to the exact day. After determining the window of opportunity though the help of the Dasas, finding a relevant Event Trigger will reveal the exact day that the event takes place. Using this technique with Vimshottari Dasa allowed me to predict the day I met my wife. Using Event Triggers is a lot of fun – it is a lot of fun to predict the exact day of an event!
The most involved way as well as the most accurate use of Transits allows for making Perfect Predictions on all areas of life without any use of Dasas – predictions are all done through transits alone. This technique requires a lot of calculations, heavy use of Vargas and it is fail proof, IF the birth time is correct. If the birth time is a bit off, then an astrologer will be better off using Dasas to make their predictions which, when combined with intuition, can get around a couple minutes of wrong birth time better than can a perfectly scientific technique such as this. So the one liability of making all predictions with transits alone is that the chart must first be examined in the light of past events and its time adjusted to perfection. I probably will not be teaching this technique until I have finished building a rectification module that uses the technique to correct even the smallest errors in birth times.
Mundane Astrology, the predicting of world events, is largely done through the use of transits and through the use of transit charts, meaning calculating a horoscope for the moment of some important planetary event, such as the Sun coming to the Vernal Equinox each year, the time of exact eclipse, or the time of the Sun entering Ardra Nakshatra (at which point the Earth is closest to the Galactic Center).
As can be seen, transits deserve a lifetime of study; the place to begin with is Gocara from the Moon, which, thanks to its simplicity, can be used effectively with little practice.