In 2012, I wrote a blog titled Private Cloud: 'Everyone's Got One, Where's Yours?' which looked at the perception of private cloud versus the reality of the environments that carry this name. Although reported interest and adoption were high, most environments fell short of the basic characteristics of cloud. Almost 1.5 years later, Forrester continues to see interest in and reported adoption of private cloud — according to Forrester's Hardware Survey, in 2014, 55% of North American and European enterprises plan to prioritize building an internal private cloud, and 33% already having adopted private cloud. Despite the increased awareness in private cloud shortcomings, Forrester found that only 1/4 of these "private cloud" environments establish self-service access for its users. What's most interesting is that most of these enterprises aren't looking to private cloud for cloud-specific benefits. 

Through a series of interviews and inquiries, Forrester recognized that cloud administrators overseeing cloud-washed environments often adopt private cloud software but intentionally don't enable some of the core features. Why? It's not a priority. It's focus for private cloud centers on non-cloud-specific benefits such as improved manageability of its virtualized environment, cost reduction, consolidation, and incremental improvements to current state — all of which is accomplished using a private cloud software solution. The ability to replicate the feel and speed of a public cloud environment wasn't a desired outcome. We found that all of our interviews fit into four standard approaches to private cloud that differ in terms of motivation, leadership, tools, budget, timeframe, and process. The four common approaches to private cloud are: 

1. Enhanced virtualization: Layering a software solution (no required infrastructure) atop an existing virtualized environment with the goal of enhancing current state of infrastructure operations, agility, and resource consumption.This is not actually a private cloud. 

2. Test/dev cloud: Using a lightweight software-only solution atop a small set of existing resources for the sole purpose of delivering fast access to resources for developers. This is either to provide an alternative to public cloud or complement to public cloud usage.

3. Public-cloud-lite: Creating an alternative to public cloud that can serve more workloads, accommodate greater customization, and use existing internal resources while still prioritizing the speed of delivery associated with a public cloud. This is driven from within line-of-business (LOB)-aligned IT.

4. Transformational cloud: Embracing cloud as a transformational technology and implementing it more pervasively using a variety of methods.

For more information on these different approaches to private cloud, see my recent report Four Common Private Cloud Strategies which describes the motivation behind each, its leaders, typical budget and core selection criteria for each strategy.