I'm always amazed that an IT department needs to be justified in this day & age but I understand what you mean. IT is misunderstood routinely. I think one major 'big picture' issue that should be discussed with management of any company is what their goals are and what their future plans will be. Until they can answer that, creating an IT department may be putting the cart before the horse. That said, it sounds like your company is moving forward and growing and managing multiple sites will require at least one body per site. If your company doesn't see IT valuable and necessary I'm not sure how they can expect to grow. Just the physical layout of your company with remote sites will produce a need by default. I've worked in a company where one guy was trying to manage exactly the type of configuration you find yourself in--remote sites, growing staff, growing tech demands, etc.--and let me tell you if was a mess when I started there simply because it was unmanageable. IT is very time consuming and NOT always in a 9-5 schedule. You'll be surprised that even 100 users, while seemingly small, will place heavy demands on your time and resources as the business grows. I think you just need to set up a formal meeting and ask---then go from there. Justification of a dedicated IT department doesn't seem that unreasonable especially if your managers expect to grow quickly.