I am not trying to slight your ability or your intent but because this involves a factory I think it best for you to consider getting the help of a local expert. If you are having to ask for help with what is a simple LAN / Intranet IP scheme then you should not be attempting to connect your company's network to the IP cameras and NVR along with the Internet. You don't want to be the one they could blame for a ransomware attack, even if your actions have nothing to do with it....I can almost guarantee you'd be blamed.
For local help and pricing, I suggest you do this: Go to the Better Business Bureau
here. Up at the top, type in to search for "video surveillance systems" or similar and type in your city, state. I suggest you deal only with the ones accredited by the BBB and with an A+ rating.
I also suggest the category "video surveillance systems" instead of "computer networking" because most people that have worked with IP-based cameras and NVR's have some network savvy but many computer network specialists have NOT dealt with IP-based surveillance devices. Of course, YMMV.
Call several and explain your situation and if they tell you they can handle, then ask for a quote. Hopefully your company will approve the quote.
IMPORTANT: If your company insists that you perform the work yourself, I would NOT do it without having the company sign a waiver that absolves you of any liability. This likely will require you to consult an attorney.
If you think I'm over reacting, then you have not been paying attention to recent news articles. The cyber attacks that install ransomware are not going after home networks, they are going after factories, meat processors, health care providers, hospitals, pipelines....companies with money that stand to lose more if they don't pay the ransom.