The error message seems to be clear and easy:
Undefined function or variable 'functionOutageFormula'.
There is no M-file called "functionOutageFormula.m" and no local function with this name also. A bold guess is, that you want "OutageFormula" instead.
You have read the message also. Then please explain, why you assume that "functionOutageFormula" is an existing function. Maybe you have created such a function, but forgot to include its parent folder in th Matlab path? Then see doc addpath.