A couple of questions for dispatchers here:
1. Where you work, how and who decides when a new hire dispatcher is ready to work independently?
2. Is OJT documented, in terms of items seen and done in a given day, how many hours of OJT accomplished, etc.?
3. Are there minimum OJT hours established before a dispatcher is released to work on their own?
4. How about a maximum, if someone is not making the grade? Or does that ever happen?
Depending on the rules of the company you dx for, it will greatly matter on what the person or persons conducting your OJT feel in regards to your passing the comp check.
Most places have an OJT curriculum that covers the all basic asspects of handeling daily dx ops. Usually you will work a full shift with whomever your trainer is, so the number of daily hours depends on how long the shift is shceduled to last.
There is a requried minimum amount of hours that must be spent in your airlines ground school and OJT, these hours are approved by the FAA. A carrier can superceed those hours, but not go beneath the mins.
For your final question, once you've completed the minumum hours or more and recommended for the comp check, you have to pass that. If not then you will most likely wind up going back for more OJT, which could either focus on your diffencies or what you covered the first time or both. A note here, the person conducting your comp check is usually very well experienced in the dispatch procedures for that particular company, they tend to know a great deal about dx procedures and the equipment being used, that said they usually can pin point any certian areas in which you lack. Depending on how well you preform overall, the person has the leverage to rate what you lack in experience on the 'grand scheme' and can pass you with recomending areas you should become more faimliar with, or if your just bombing the entire thing, they can try to assess where to focus additional OJT traning. Usually one who preforms poorly overall manages at least a satisfactory result in the second check. If someone goes that far and still bombs, well, they should hope there company needs their services eleswhere.
Please note the above answer is not definate and how a comp check failure is handled can vary from airline to airline.