Might worth to ask if you can shoot the exterior during sunrise/sunset (depending on which direction is facing the sun). This is outside of normal working hours of course and they might decline. So explain why it would result in better photos.

I don't know how this factory works but probably need to make sure anyone you photograph is wearing appropriate safety gear for the task/location. Including yourself, of course.

Bosses would appreciate some portraits shoots as well

You'll need wide shots to show the place (using 28 mm) and some detailed shots e.g. people working (using 55 mm).

for something more specific, read up on keystoning. It's about making sure your lines are straight.