Choosing between public and private cloud as a strategic decision is a misleading distraction, a red herring. The strategic and transformative decision is the choosing of the Cloud (or not). Private or public is a tactical follow-up.
Clearly, choosing to host an application and its data in-house or with external provider is a choice of substantial immediate impact. But it is not transformative. The strategic value of Cloud computing for a business and its IT organization is not in the hosting and sourcing arrangements. It is the transformation of IT from a custom technology shop to a retail store-front of reusable pre-assembled technology stacks offered as services.
I like to compare this transformation to the difference between ordering of a new outfit from a tailor vs. buying it at a retail store. Custom tailoring can produce unique results, but is expensive, slow and depends on your and the tailor’s talents. A retail store will offer a number of different designs to choose from, but none are specially arranged for you. This approach is somewhat limiting, but allows faster time-to market, lower costs, greater agility and on the whole better quality of service as the economy of scales allows the provider to hire top talent and deploy state-of-the art technology. No wonder that the notion of Cloud computing has been championed, if not invented, by a leading retailer, Amazon.
Enterprise IT, quite similarly, is dominated by technology assemblies that are custom-designed for each new software project. It will, also quite similarly, transition to the Cloud arrangement where project leaders select suitable software stacks from the available pre-assembled general-use patterns, managed by the cloud provider on their behalf.
Both private and public providers will compete for the business. And even for the internal provider, the best practice ought to be “public-first”: even when deploying in-house, public cloud characteristics, such as
- design for potential massive scale,
- closely-controlled multi-tenancy,
- strict isolation from subscribers,
- tracked billable resource consumption and
- openness to change and growth.
are just better design principles. For the majority of IT organizations having followed these principles will turn out to be very fortuitous as they consider, in the future, offering some of their data and services to the outside communities or public subscribers.
In summary then:
- The transformational impact of cloud computing is not in the shifting from internal to external hosting of software, but in the way that IT resources are organized, managed and consumed.
- The core impact of the Cloud is the transformational shift in IT from custom to “retail”; from building custom assemblies of software for each IT project to choosing from a list of pre-assembled, integrated and certified stacks from a self-service “retail store-front”.
- Private and public, local and remote providers will compete to fulfill the requirements of new subscribers. A subscriber in a well-designed cloud environment does not know if the service they provision is fulfilled internally or externally, by a private or public cloud provider.
- This shift applies equally to IaaS, PaaS and SaaS services. A well-designed cloud provider and cloud subscriber environments will not be exclusively IaaS, PaaS or SaaS, but rather will support all three categories of services in a uniform way. All are simply the entries in the catalog of available services.
- The well-defined characteristics of cloud computing, including elastic scalability, sharing of resources, use tracking and others – are the essential means to deliver a well-functioning cloud-provider environment, but not the ultimate goal or outcome of cloud computing.