Ultimately, companies are unlikely to fund a desktop virtualisation project until the numbers look good. How can you build a good return on investment case for virtualising your desktop infrastructure?
One of the problems with building an economic case for desktop virtualisation is the initial capital expenditure involved, explains Rajendra Deshpande, chief technology officer at Intelenet, a business process outsourcing provider.
“Typically, the initial investment will be higher, which means that the justification for that investment becomes more challenging and needs to be proven,” he points out.
Anything that can be done to reduce up-front capex will therefore ease the transition to a virtual desktop environment. This could include not refreshing desktop hardware. Microsoft’s Ian Moulster suggests reusing old PCs where possible.
Live long and prosper
“By turning your old PCs into thin clients you can stretch their lifespans. Also, implementing applications streaming technology such as App-V has low up-front costs and a fast ROI – you don’t have to dive straight into VDI, which can require a heavy server and network investment,” he says.
Last year, Forrester carried out an ROI analysis on a school in the US that is using Citrix XenDesktop to deliver virtual desktops to 1,500 PCs over three years. The experience of the school – which achieved an ROI of 170 per cent in five months – shouldn’t be taken as indicative of the ROI attainable with other products, but the evaluation framework provides a good set of guidelines to build a business case, Forrester pointed out.
The ROI study found savings in several key areas. Avoiding a PC refresh saved it money, as did the cost of new server hardware, thanks to the back-end virtualisation effort. It saved money on software licencing, and improved the efficiency of IT staff. Those staff made particular management gains in application upgrades and desktop provisioning.
Most interesting about the Forrester study is the total economic impact (TEI) framework it used, which provides some useful guidance for IT managers projecting cost savings. It broke cost inputs down into areas including software licensing for whatever you’re using on the client and server side.
The situation here will depend on the vendor. For example, Microsoft offers Virtual Desktop Access licencing for free with PCs covered by Software Assurance or separately for thin clients. Client-side hardware costs can be an area of particular savings, says Mark Bowker, analyst at Enterprise Strategy Group.
“We see universities and colleges looking at desktop virtualisation to extend the existing lifespan of the desktop,” he explains.”This hardware won’t support new applications, but with desktop virtualisation you can deliver performance and predictability on an existing hardware platform.”
However, some of these savings can be offset by capital expenditure in the data centre. Server hardware may need to be refreshed with more powerful boxes, for example.
Storage costs can take a considerable chunk of a project budget, especially if a company is starting from an immature position, such as local storage on departmental servers, for example. Then, there are networking costs to consider.
Networks in the data centre may need to be upgraded for speed, and some more resilience might be needed in LANs closer to the desktop.
Finally, there are administration costs to consider. In the Forrester case study, these involved creating images and requirements for individual applications. The analyst firm expected the time taken to manage the systems to fall, as the creation of application images is a one-time event.
Just as difficult
These latter costs shouldn’t be underestimated, warns Ewen Anderson, managing director of Centralis, a desktop migration consulting firm. “A lot of early calculators around ROI say ‘it costs this much to maintain a physical PC’,” he says, “but a lot of the processes for creating the virtualised applications are just as difficult.”
The more fragmented and arcane an organisation’s application base, then, the greater a proportion of the project that cost is likely to represent.
Microsoft, has estimated that the cost of a full VDI implementation will be roughly 11 per cent more than a distributed PC-based environment.
There are some upsides, however. The security gains involved in centralising information effectively rolls discrete security costs into operational expenditure, and so represents hidden cost savings.
Worker flexibility also represents a big gain. How much will a company save by enabling staff to be operational at home when they don’t want to travel to the city because of a flu epidemic? It is important to look at the immediate numbers, but in doing so, don’t lost sight of the bigger, more nuanced picture.