How long can i cook a bone in Pork Shoulder? I have cooked bone in pork shoulder many times before and I am about to do it again but I feel the need to experiment slightly...
My plan is to cook the pork shoulder in the oven for 8 hours at 100 degrees celcius (212 degrees faranheit) then transfer it to my smoker, where i shall smoke it for another 8 hours between 90-100 degrees celcius (194-212 degrees faranheit).  I'll have internal thermometers etc so i know it will hit the correct temps, i am just wondering if I will end up drying the crap out of it.  I can't give a weight on the pork shoulder as I don't have it yet, it will be the entire shoulder though around 4.5 kg maybe

What do people think, good plan or bad plan?

I will be using a temperature probe, I forgot to mention that there would also be a cider bath in the oven and smoker as well. Can't change the order of the cook as I won't be there for the time it spends in the oven (I would have just gone for smoker straight through if I had). Thanks for your advice, I'll let you know how it goes.
Don't cook by time, cook it until it's done (you can slide a probe into all parts of the shoulder with practically zero resistance. That said, 16 hours for a 4.5 kg (10 pound) shoulder doesn't seem outrageous. In fact, at those cooking temperatures, I would be surprised if your pork was done cooking by then. Bear in mind, I am assuming that your intention is to make pulled/shredded pork.

I would suggest starting the shoulder in your smoker, and transferring it to your oven to finish, rather than vice versa. The reason you would want to do this is because you can kick up the temperature in your oven to speed cooking and get past the stall. Temperature control will be much easier in the oven, and it will be the latter part of cooking where you would want to vary temperatures. Otherwise, you are dooming yourself to being stuck waiting an extra 3-4 hours waiting for your shoulder to finish cooking.