Performance Center - Support Tip : Understanding Virtual User Days (VUDs)
This article explain how virtual User Days work, provides a general guidance of how theu should be used and sample scenarios, very useful if additionla licenses are required for ocasional big Load Test or if you currently work using VUDs
Link in Knowledge base: http://support.openview.hp.com/selfsolve/document/KM00514272
HP LR/PC Support
If you are customer you can try posting on our internal forums for more personalized support.
If you find that this or any post resolves your issue, please be sure to mark it as an accepted solution.