In May, we published our first installment of Cloud Possible: Mission Critical for Utilities, we explored Public and Private cloud, the 2 primary cloud deployment models and the considerations for mission critical applications for Utilities. In this installment, we’ve decided to break it up into shorter more frequent posts, but we’ll introduce three Cloud Service Models: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). In future installments we will evaluate each of these models. Much like in our first installment, we’re reviewing some content that’s been around for a while now – but we’re addressing this in the context of mission critical enterprise applications. As always we are looking at it specifically for utilities, where for valid reasons, cloud adoption may be less common than in other industries. As we begin this installment, it’s important to note that evaluation of these models will require an understanding and desire for simplification, efficiency and economies of using multi-tenant cloud provider services, balanced against the requirements to maintain the control, flexibility, and ability to customize in order to deliver productive and compliant applications to stakeholders.
While all three models include off-premise hosting of your solutions, they differ in the support functions that will be the responsibility of the Cloud Service Provider (CSP) versus those that are to be performed by the Utility. For the purpose of our discussion, we are using a 7-layer operating and support stack to outline the responsibility matrix for each of the three models (see Figure 1). We will review the responsibilities of each model, the corresponding attributes, and then outline the implications to your end user support model and security plan compliance.
Before we dive into the specifics of each model, I’d like to introduce a transportation analogy – a concept that came from a WebSpecia blog using a common, everyday example to illustrate concepts in the operating model. I like this analogy because it provides a simple, everyday use case to depict the trade-off between simplicity and efficiency versus control and flexibility referenced earlier.
The analogy compares owning a vehicle, leasing a vehicle, using a taxi or Uber, and public transportation. Owning a vehicle is very much like today’s on-premises computing model, where you control and are responsible for the entire operating stack. IaaS is like leasing a car (with maintenance package), you still have responsibility for driving, wear and tear, adding fuel, and washing your car, but you maintain control of the car’s model, color and features…and where and when you decide to drive it. PaaS is like using a Taxi or Uber, you maintain control of the time you want to leave and get to your desired destination, but leave the vehicle choice, ownership, maintenance, and operation to the vendor. Lastly, SaaS is like public transportation, where the vendor offers pre-determined options for schedule and destination, and you have no operating responsibilities.
With this conceptual analogy as a reference point, in our next posts we will explore each cloud operating model and the implications of each. As always, this will be from a utilities point of view.
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