Cummins' normal layoff cycle is 3 years, so with the last mass layoff of salaried employees being the 4th Quarter of 2015, you should be good until the 4th Quarter of 2018. They never "need" to layoff employees, however if at the end of the year, profits are down, they sacrifice salaried employees to show shareholders that they are making an effort to control costs....
Happened roughly every 3 years since I hired in there in 89 and in each instance, 500-1500 local salaried employees were out the door and if you take the severance package, then you can never every go back there. The only upside would be if you are Indian or Chinese, because that is where they are shifting all of the technical work to save cost over "expensive" domestic engineers.