Looking for suggestions on how much to serve on meat. They would like pulled pork, ribs, and brisket
When you visit your local BBQ places you normally see a few standard options.
For the pulled pork and brisket, it is usually sold by weight. I believe a 1/2 Pound portion is the most common from my experience of eating BBQ with friends.
For ribs, they are normally sold by half rack or full rack. A full rack is a lot of food so I would not think anyone would expect to eat that at a BBQ. You would probably be good with 5 or 6 ribs per guest.
These amounts of meat per person along with some popular BBQ side dishes in your area should provide plenty of food for your guests.
The big part is figuring out who wants what meat. If you already know then you can easily plan for that. If you don't know you can do enough for 10 of each and let your guests fight over who gets what. If it was me, I would probably make enough of each meat for 15 people. That should assure nobody goes home hungry and you will probably have enough left overs for a few days.
If you aren't able to get food orders from everyone attending ahead of time, you should start by making enough for each guest to have 1 serving each of pulled pork, ribs, and brisket. I'd say 6 ribs is one serving and 4 oz (cooked weight) is standard for the other meats. Then, as a buffer, I would add on a couple more servings of each meat, depending on how much money I was making from the catering job and factoring in the food costs. For instance, if brisket costs less than pulled pork, I would include more extra servings of brisket than pork. I would not send along more than 15% extra servings of each of the meats though, since not everyone at the event will be having one serving of each meat, but 1 serving for each person really ought to be be the minimum, if this is a professional job, because your reputation may be affected. The perception that the caterer did not provide enough food isn't likely to help out your business. If it's a casual thing, for family or friends, then you could get by with less, as stated above, and have people fight over which meats they get.