Desktop virtualization comprises of many different types of virtual desktops. One option is to use a Hosted Shared Desktop model, which consists of a published desktop running on a Citrix XenApp server.
One of the goals when creating a design for Hosted Shared Desktops is to try and maximize scalability while still providing an adequate user experience. Hosted Shared Desktops provide an advantage over other desktop virtualization techniques by only requiring the use of a single operating system, which significantly reduces user resource requirements and helps improve scalability numbers.
However, in order to get the most users, making correct design decisions as to the resource allocation is important. Creating too many virtual machines or too few might negatively impact scalability.
This planning guide provides best practices for virtualizing Citrix XenApp. Even though these best practices are based on the Hosted Shared Desktop model, they are still relevant in a non-desktop model where users only connect to published applications without the desktop interface.