Missing Assets

I am just reviewing my Workstations for an Corporate review and have noticed that there are Workstations that were showing in December that are no longer in our asset list. I thought it odd that we all of a sudden had software licenses that were not being used. I checked with my technicians and they told me they have not been on the asset module since before Christmas. Nothing was deleted. We are currently missing at least 4 workstations that have been there since we started using the SDP On Demand. This is what I have noticed from one of our remote locations. I have not even checked the other locations.

Thanks,

Liam