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Migrating to the Cloud


So if your organisation hasn’t made the move yet, what are your options? There are 3 main approaches when migrating to the cloud:

  • Infrastructure as a Service (IaaS),

  • Platform as a Service (PaaS), and

  • Software as a Service (SaaS).

This article looks at these approaches in detail and provides the benefits and disadvantages of each.

Infrastructure as a Service (IaaS) WHAT IS IaaS? IaaS involves migrating your current applications to hardware within datacentres. Users access the applications via an internet connection.

THE IaaS APPROACH With IaaS, organisations can quickly take advantage of cost savings by reducing the costs involved in purchasing and maintaining hardware. IaaS is particularly valuable to growing businesses as they are able to acquire resources quickly and scale them back as demand diminishes. Applications do not need modification before migrating to an IaaS model thus organisations can take advantage of the benefits quickly with minimal investment. Benefits of IaaS

  • Reduce costs associated with maintaining hardware

  • Eliminate excess capacity of unused hardware as resources can be acquired or scaled back as required

  • Facilitate business growth as hardware resources can be required quickly

Disadvantages of IaaS

  • If the provider goes offline, users cannot access the application. This emphasises the importance of choosing a reputable provider

  • Some industries require that organisations advise where their data is stored. Often datacentres can be located in other countries which could pose a compliance risk

Platform as a Service (PaaS) WHAT IS PaaS? Platform as a Service (PaaS) provides the underlying services required to develop and run an application in addition to the necessary hardware.

THE PaaS APPROACH PaaS can be considered a viable option for both new and existing applications. As the underlying services are made available on the platform, new applications can be developed quickly with the additional benefit of reduced costs associated with hardware ownership and maintenance.

Existing applications can be migrated to a cloud platform but often require modifications to ensure compatibility. Organisations need to consider the extent of modifications required to ensure the cost of the migration to the cloud does not outweigh the benefits. Organisations also need to be wary of platform lock-in – once entrenched within a platform it may be difficult to switch to another in the future without considerable cost.

As with IaaS, organisations benefit from reduced hardware associated costs and are able to acquire and scale back access to applications as required. Benefits of PaaS

  • Applications can be developed quickly at a reduced cost as the necessary components are in place

  • As with IaaS, hardware associated costs are significantly reduced

Disadvantages of PaaS

  • Existing applications may need modification to take full advantage of the platform

  • Depending on the platform chosen, existing applications may need to be rewritten if they are not compatible

  • Organisations could be locked-in to the platform, particularly for business critical applications, and may find it costly to move to another platform in the future

Software as a Service (SaaS) WHAT IS SaaS? SaaS refers to third-party applications that are provided through the cloud. Unlike the traditional software model, these applications are purchased through a subscription basis rather than a one-off purchase of the software. Although organisations do not own the application, they do own their data within the application.

THE SaaS APPROACH Organisations gain access to applications they would otherwise have to purchase outright at a fraction of the cost. However, they should be cautious of locking themselves into a vendor which could pose a risk should a vendor suddenly go down.

Organisations also benefit from automated updates to the software and the cost reduction in hardware associated costs. Benefits of SaaS

  • Gain access to business applications without a substantial initial outlay

  • Ability to move to other applications with minimal risk as heavy investment is avoided

  • Automated updates by the vendor reduce the need for maintenance of an application

Disadvantages of SaaS

  • Access to applications – and sometimes business critical information – can be interrupted if the provider goes down

  • A switch to another provider could cause significant disturbance if locked into a vendor – particularly if the application is business critical

Which approach is right for you? The most ideal approach for migrating to the cloud depends on the individual needs of each organisation.

Businesses with existing applications that want to migrate to the cloud could consider the IaaS or PaaS approach. With the PaaS approach, companies need to determine the extent of modifications required for the application to be compatible with the platform. If modifications are extensive, it would be best for an organisation to select the IaaS approach.

However, if modifications are minor, organisations would benefit from the PaaS approach. Companies looking to develop new applications would benefit from the PaaS approach as they are given access to the underlying services to quickly develop a functional application. Businesses need to be wary that they do not get locked into a platform as moving to another platform could be difficult at a later stage.

Before developing their own cloud applications, organisations should take advantage of what is commercially available. SaaS could be an option for businesses looking to quickly gain access to a business application without the initial outlay. Companies opting for the SaaS approach also benefit from automated updates and reduced maintenance costs. However, organisations need to be cautious of locking themselves into a vendor as switching could be difficult in the future.

There are also generic cloud benefits that enterprises will realise no matter which migration approach they select. With all 3 options, organisations benefit from a reduction in costs associated with hardware purchase and maintenance.

Before migrating to the cloud companies need to consider whether migration would pose a compliance risk given that datacentres are scattered around the world. Businesses also need to consider the potential security threat of their data and the ability to retrieve their data should a vendor go down.

With a well thought out plan, organisations can successfully migrate to the cloud using any of the options – IaaS, PaaS, SaaS.


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