Accounting roadmap for growing IT firm

Hi there!

I am the controller at my company. We do IT consulting and managed services for monthly monitoring. We have 24 employees, 100 active clients and do 4.5 million in revenue.

I am trying to come up with a road map for the accounting department as we grow in phases. Currently, I have an assistant but pretty much perform all accounting/ HR duties myself.

Can anyone share how their org has grown in the financial departments... things that worked well. moves that were made too fast or too slow. Just any general advice I can take into account to phase this out properly with hiring, breaking into departments, etc.

End result or at least results way down the road before i start reinventing again lol) is to break all areas (ie. purchasing, service, project, sales, etc.) into entities with their own income statements and likley shared balance sheets. This will probably require 1 director of finance, 1 controller, 1 HR and maybe 3-4 accountants.

So I am trying to figure out how many phases and how I should get there.Any advice would be greatly appreciated!!