Code:
  public static void main(String[]args){ 
  double ms=0, mss, msss, mssss, CPU; int input,charc,unit,unit1,unit2,unit3,unit4,card,output,lines,inst; 
  double sec=.010;
when you give a value to a variable inside an if
it is not certain that it will actually get a value!
that is why you get this error.