If you’re going to interview for a control systems job in a plant, they’ll ask you a lot of questions, but you should also have some questions for them. To me, these are the minimum questions you need to ask to determine if a future employer is worth pursuing:

1. Do you have up-to-date electrical drawings in every electrical panel? – When the line is down, you don’t have time to go digging.
2. Do you have a wireless network throughout the plant? – It should go without saying, having good reliable wireless connectivity all over your facility really helps when you’re troubleshooting issues. Got a problem with a sensor? Just setup your laptop next to the sensor, go online, look at the logic, and flag the sensor. You don’t have time to walk all over.
3. Does every PC (including on-machine PCs) have virus protection that updates automatically? – We’re living in a post Stuxnet world. Enough said.
4. Have you separated the office network from the industrial network? – Protection and security are applied in layers. There’s no need for Jack and Jill in accounting to be pinging your PLCs.
5. What is your backup (and restore) policy? – Any production-critical machine must always have up-to date code stored in a known location (on a server or in a source control system), it must be backed up regularly, and you have to test your backups by doing regular restores.
6. Are employees compensated for working extra hours? – Nothing raises a red flag about a company’s competency more than expecting 60+ hour weeks but not paying you overtime. It means they’re reactive, not proactive. It means they don’t value experience (experienced employees have families and can’t spend as much time at the office). It probably means they scored poorly in the previous questions.

You don’t have to find a company that gets perfect on this test, but if they miss more than one or two, that’s a warning sign. If they do well, they’re a proactive company, and proactive companies are sane places to work.

Good luck!