What is Infrastructure as a Service (IaaS)?

Infrastructure as a Service (IaaS) is best visualised as sitting at the base of a three-tier Cloud computing pyramid that also comprises PaaS (Platform as a Service) in the middle and SaaS (Software as a Service), at the top. The amount of customer control over the virtualised IT resources increases as you descend the pyramid.

Cloud Computing Pyramid - IaaS, PaaS, SaaSAn easy way of thinking of IaaS is hardware-as-a-service: servers, storage, network infrastructure, data centre space owned and pooled by specialist third parties and offered as a fully outsourced, metered service on demand.

Customers are then free to manage the operating system, middleware and applications typically via self-service provisioning portals.

The evolution of IaaS

Where once IaaS was bought as a straightforward outsourcing choice, today it is increasingly featuring in hybrid Cloud deployments, with organisations mixing on and off-premise infrastructure to create more tailored computing platforms as well as in SaaS models where software vendors want to offer their solutions as a cloud services without investing into infrastructure themselves. And as IaaS has matured so has organisations’ willingness to use it for more than low value development and storage requirements; business-critical systems are now an IaaS staple, with only highly intensive applications and those with extreme data sensitivities showing resistance to a move.

Why should organisations consider IaaS?

With its ability to offer scalable, commoditised and virtualised operating environments of almost infinite capacity, and with its characteristic opex-based costs model, IaaS can:

  • Allow new organisations to invest in hardware without upfront capital
  • Underpin rapid organisational expansion through speed of on-demand provisioning
  • Boost time to market through accelerated deployments
  • Enable alignment of resources to business needs, especially where infrastructure demands may be volatile
  • Take the pain out of substantial legacy refresh
  • Create the foundations for business continuity
  • Facilitate planning and budgeting through greater cost certainty
  • Encourage a greater focus on adding value at the front end rather than on ‘keeping the lights on’ activity
  • Drive down Total Cost of Ownership and carbon impact

The benefits of IaaS

FeatureBenefit
Replaces or supplements infrastructure Time, cost and resource-effective means of keeping IT aligned with operational needs
No CAPEX required Greater affordability removes barriers to provisioning and encourages more agile response
Control without constraint Complete management of platform and total flexibility without the distraction of ‘keeping the lights on’
Predictable OPEX Cost certainty aids cashflow, budgeting and planning
Infinite elasticity Resources can flex up and down to match needs precisely and eliminate waste
Rapid deployment Improved time to market and sharper competitive edge
Built-in redundancy Inherent strengthening of business continuity and disaster recovery capability
Optimised security Safeguarding by specialists of business critical operating environment

 

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