Very general question, in your question you are assuming that you have 15bbs left , 15bbs is relatively big stack in a turbo/hyper and relatively shortish stack in a regular speed tournament.In a regular speed tournament 15bbs is the threshold of start thinking the open shove move or 3bet shove against other player's open raise.
If you are the player with the action in an unopened pot then with 15bbs I think that you should open kinda tight or if you open wider at least you must know who are the opponents behind you to act,it would be a bad idea to open raise light and face a shove.It is better to have a plan before we act.
Another factor that many players don't take into consideration is how many players behind them have shovable stacks[5bbs-20bbs/depends on the speed of the tournament again].
So once again I tried to give you a piece of advice here but there is not a formula. Also search on the internet for some push fold charts for short stack plays.