Desktop virtualisation – avoid dogma and conventional wisdom

Many large enterprises struggle with the business case for strategic desktop virtualisation. Conventional wisdom is that virtual desktop infrastructure (VDI) is more expensive than commodity PCs and this is amplified by simplistic cost models.

For enterprises eager to exploit the many benefits of VDI, there is a pragmatic way forward.

Managed diversity and continuous innovation

Enterprise IT organisations understand that a hybrid end-user computing platform supports the needs of their customers. A hybrid platform combines physical, virtual and cloud technologies to deliver tiered service to the business. VDI will be the most appropriate platform for many users; others will benefit from a physical desktop, laptop or mobile device. Devolved components of a hybrid can evolve at different velocities, enabling continuous innovation to replace traditional big-bang transformations.

Overall the platform must be manageable but endpoints can become increasingly diverse. Smartphones and tablets already combine with SaaS and corporate app stores, and the business case for large-scale VDI only makes sense within this concept of managed diversity.

Avoid dogma and conventional wisdom

A common initial perception is that VDI has a higher capital cost than physical PCs but a lower operational cost. Most enterprises find that in reality, it depends.

• For example, a large retailer will have hundreds of branches. There are organisations making multimillion-pound savings by stacking virtual desktops in a central datacentre and removing distributed management infrastructure. These organisations deploy VDI to reduce capital costs.

• Conversely, large IT organisations understand their own support costs much better than their suppliers do. They know that the vast majority of their service tickets relate to password resets, application issues, BlackBerrys, print devices, and so forth – they know that VDI will not reduce service tickets and don't swallow vendor-supplied cost models.

Develop your own strategy

There are steps an enterprise can take to understand the real costs of a hybrid platform.

First, define the tiered services that will meet the needs of your major user groups. Define functionality, support, service levels and unified communications and iterate with representatives from key business units. Typically there will be services based on VDI, desktops and laptops.

The next stage is to develop a cost model for each service definition, using realistic operational costs. The model should include capex, deployment, supporting infrastructure, and opex over a period of three to five years. The model should be parameterised so that changing the spread of users between the services is reflected in the overall capital and revenue costs of operating the infrastructure.

Finally, user populations are mapped to the service offerings, refining the service levels and cost models if necessary. In some cases user groups might receive multiple services. For example, some users might be allocated a physical desktop for their day job and a remote-access virtual desktop for accessing email and files from home. VDI costs will be less expensive in some circumstances but not in others.

This approach creates a complete, realistic understanding of costs and options that underpins a comprehensive, strategic understanding of the business cases and end goals. Enterprises are empowered to move beyond dogma and focus on managed diversity and continuous innovation.

Tommy Armstrong is co-founder and partner at Virtual Clarity