Generally business classifies expenditures in to two categories; Capital and Operational. The following is a discussion of where to expect real cost savings in your Desktop Virtualization project.
The accountant in the office next to me describes Capital Expenses (CAPEX) as one-time costs that are an investment in an "asset" that the company expects to provide service for an extended period of time. An example would be a factory (and the hardware and software within it). Operating Expenses (OPEX) on the other hand includes the costs required to maintain and support the asset.
Most desktop virtualization solutions save money on OPEX, and some (but not all) save CAPEX. With some solutions the cost of buying and installing desktop virtualization solution is about the same cost as rolling out physical desktops for those same users. This reflects the day of $600 desktop PC's and $400 terminals. The big cost savings comes from lower management costs.
The problem is that CAPEX is a relatively straightforward expense to quantify. It's easy to determine how much you've spent on hardware, software and implementation. So the expense of virtual desktops versus the expense of physical desktops is a simple calculation.
OPEX, on the other hand, is much more difficult to quantify, for two reasons:
For example, are you including things like "productivity gained by less downtime" or "power savings by going to thin clients" in your OPEX? ROI models are something that JDL would be happy to help with.
The bottom line is that most people implement desktop virtualization to save money, and most people do actually realize those savings. But it's important to figure out what you're saving for both CAPEX and OPEX, and to figure out what will and will not be included in your OPEX calculations.
Let us know if we can assist in developing an ROI for a potential project for you.