Not only will this result in three operations, three times the (minimal) risks, and three time the recovery, it will cost you LOTS more. I hope that greed is not the motivation of your surgeon, but let's assume it's not. Why would a surgeon with proper training, board-certification (American Board of Plastic Surgery), experience, and skill recommend three separate operations when one can be safely performed with one set of risks and one time off work for recovery?
Depending on your size, a tummy tuck should take no more than 3 hours, perhaps less. This includes umbilical transposition, entire breast bone to pubic bone muscle plication, and layered closure with dissolving sutures beneath the skin (no staples or external sutures to leave marks). A full Wise pattern breast lift with similar closure technique should take no more than 3 hours, and implant placement adds another 45 minutes. With proper OR table padding, urinary catheter (removed before you wake up in the recovery room), Bair Hugger warming in the OR, and pneumatic boots to keep the blood moving in your legs (decreases the risk of blood clots), you are at extremely low risk for any operative-time-related complications. Three operations simply triples these same risks! I routinely do 6,7, and occasionally up to 8 hour-long operations as OUTPATIENT procedures, but this requires expert anesthesia and use of IV general anesthesia rather than inhalation gas anesthesia. It also requires enough surgical skill, experience, and celerity (speed) to do all of these operations expertly with minimal blood loss
Some plastic surgeons are uncomfortable doing full breast lifts AND implant augmentation at the same time. If his justification for doing the breast surgery in two operations is to decrease the risk of double bubble formation, perhaps this betrays a history of bad outcomes that stimulate this way of thinking. I accept nothing less than the best outcomes possible, and I must say that MOST plastic surgeons are not only capable, but prefer doing both parts of breast lift plus augmentation surgery at the SAME operation. (There IS a way to minimize double bubble formation, but this technique is not the way most of us were trained to do this (lift + implants) operation). I would be happy to discuss this technique with anyone interested--it's not magic, just good planning and technique.
In short, I sense extreme conservatism in your doctor, perhaps because of speed (slowness) of operating, lack of experience with one or more of these procedures, difficulty with anesthesia management for longer operations (sometimes out of the surgeon's control unless he/she own their own surgical facility as I do), or perhaps restrictions of the operating facility (some outpatient surgicenters require shorter procedures, or restrict the surgeon to specific "block times"). If your surgeon operates out of a hospital, perhaps he's trying to reduce the possibility of overnight admission, which increases the costs substantially (and makes the patient angry at the surgeon). Perhaps it's simply greed (the charges for three separate operations are invariably MORE than one combined operation). Perhaps it's truly a fear for your safety if there are complicating health issues, such as Factor V Leiden, diabetes, or cardiac issues.
My best advice: get at least one more opinion (two is better yet) from well-trained, experienced, board-certified (American Board of Plastic Surgery) plastic surgeons, and ask them about multiple procedures at the same time. Virtually all of us do things that way because it is safe, effective, and best for the patient overall.