SaaS, IaaS, and PaaS are the three most important delivery models. Building on these three many other service models have become available to the market. Popular Anything as a Service models include:
Anything as a service combines the advantages of cloud service models with pooled expertise. Because, in many cases, XaaS companies service multiple clients, they have a wider range of opportunities to discover and improve upon software flaws, as well as introduce innovative features that a single company may not envision or be able to afford. It's this collective benefit that winds up adding more value in the longer run than the more immediate benefits, like cost controls, that the cloud provides. The following is a list of the significant benefits XaaS models provide.
There are potential disadvantages of using an XaaS service, and stemming from the reliance on an outside provider for the X service.
The most critical drawback is downtime. If the provider’s service goes down, making the service unreachable, all business operations that rely on that service will be disrupted. This can be mitigated by relying on a competent, reliable, industry-leading provider, or in some configurations multiple providers. To a lesser degree, performance is a second drawback. While not as potentially devastating as a critical system outage, poorly performing services can still cause disruptions, and loss of revenues.
The last disadvantage varies depending on the XaaS model service type. By employing a service model, companies effectively outsource those IT functions, and likewise part of that responsibility. Illustrated in the Accountability and Share Responsibility Model is a framework for how providers and consumers should share partnership of the data and services within their respective domains.
As the cloud service model moves from a general Infrastructure as a Service (IaaS) model to a specific Software as a Service (SaaS) model, the share of responsibility falls more heavily on the cloud service provider. Imagine renting server racks, the provider’s responsibility amounts to keeping the servers running and their connectivity strong. Beyond that, covering application-level controls and above is the responsibility of the cloud user. Whereas, providers of financial SaaS will be required to have strong identification and access controls. Data security and protection is subject to regulations, and the shared burden of the cloud provider and consumer.