Online vendor ROI calculators are meant to apply universally, but they may not fit your situation very well. Some ROI calculators present a default value of 1,500 users, a hint that very small companies may not be good candidates for UC. Be sure that you understand the Total Cost of Ownership (TCO) and the Return on Investment (ROI) of your infrastructure-to-be, as well as its implications for capital and operational cost.
The metrics you use signal how the IT department is viewed inside your company. Focus on both TOC and ROI to signal that the project impacts both the top line and the bottom line.
Use the IPT and UC Business Value Assessment Tool to brainstorm project:
The analysis will also provide you with an idea of the cost avoidance and opportunity costs matrix of going ahead with the infrastructure against doing business as usual.