In 2011, Gartner outlined 5 Rs – five strategies – for migrating applications to the cloud. These were Rehost, Replatform, Repurchase, Refactor & Retire.
Stephan Orban built on these on the AWS blog in 2016, adding another R into the mix: Retain.
When we talk with customers about the essentials of building a cloud migration strategy, we assert the importance of having a deep understanding of your existing estate (AKA where you are now) alongside clear objectives (AKA defining where you want to go).
The 6 Rs of cloud migration provide a framework for your organization to reconcile these two elements. Most successful cloud transformations use a combination of some or all of these approaches.
For those who don’t know, the 6Rs are:
Rehost (AKA Lift-and-shift) is a popular approach for large-scale migrations where avoiding large capital expenditure on IT infrastructure is attributed as a key driver. As the name suggests, it involves moving your existing estate – as is – onto the cloud.
It is a quick and cost-effective migration solution that is practical if you desire minimal impact on existing workflows. This approach will marginally save on costs, however, it does little to accelerate you towards the benefits of cloud adoption.
Having said that, it is easier to optimize and modernize applications once they are in the cloud – so there is something to be said about lift-and-shift being a good first step in the cloud.
Replatform is a similar approach to rehost but it involves making more optimizations to certain applications in the cloud. These applications will usually be tied to some key/valuable business objective.
You should consider replatforming an application or service, when the on-premise hardware or software reaches end-of-life. This is not only an opportunity to avoid CapEx investment but also to easily deliver scalability. For example, using database services. Replatforming generally offers more opportunities to realize savings than rehosting does
An example of repurchasing would be moving to a/switching SaaS provider. We noticed a lot of organizations repurchasing when the COVID-19 pandemic hit and they needed to rapidly scale mass remote working with collaboration and video conferencing solutions.
Refactoring involves re-architecting your applications using cloud native features.
Rather than just optimizing, you are reimagining applications by moving from monolithic virtual machines to a serverless architecture formed from PaaS services from your CSP.
While this approach delivers further improvements in cost-effectiveness, reliability and scalability, it can also be the most expensive and disruptive.
However, this is where true value can be seen in the cloud and where significant transformation occurs. If your objectives require refactoring, then the juice is worth the squeeze.
When you assess your existing application portfolio, you are more than likely to find apps that are no longer serving a purpose. Don’t miss the opportunity to streamline your estate – it can help manage costs, security concerns and allow you to cut away non-essential distractions, so your teams can really focus on your objectives. As the on-premises workload is reduced you’ll often find that applications used to run the data center itself are no longer needed and become retirement candidates.
Don’t expect to go completely cold turkey from your on-premises solutions. For some applications, the most sensible thing to do would be to leave them alone and wait until it makes financial sense or your cloud maturity has progressed.
We have seen more and more enterprise customers opting for hybrid cloud strategies – with scaled-down, on-premise solutions existing alongside their public cloud infrastructures – if their data and security policies are set on ensuring certain applications remain in their own data centers.
A migration strategy suited to your business needs
Deciding which of these approaches to take is a key part of building your cloud strategy. There is a lot of complexity involved, however, you can start the planning process by simply setting out six columns and listing your application estate appropriately (eg. Which apps do you want to rehost? Which do you want to retire? etc.)
As mentioned at the beginning of this post: your business objectives should drive these decisions. If your goal is to get to the cloud quickly, then rehosting and replatforming is a low-risk, cost-effective way to reach your goal.
However, if your goal is to scale your existing applications, boost agility, exploit cloud capabilities and realize greater value, you will need to invest in refactoring your apps via the PaaS services on offer from your CSP. This takes a lot more business planning, and ROI is a lot longer.
The Covid-19 pandemic forced many businesses to pull the trigger on cloud migration and digital transformation, for both business continuity reasons (scaling remote working), as well as for agility and innovation reasons (responding to rapidly changing markets).
As such, with many organizations now pushing for an accelerated cloud adoption roadmap (with faster time-to-value), we would recommend taking a lift-and-shift approach first, regardless of your overall transformation goals.
Cloud adoption initiatives require momentum. By migrating to the cloud quickly by rehosting, you build a stronger foundation for accelerating further – more transformative – initiatives in the future.
Does your organization need help with its cloud strategy? Our consulting team has helped lead successful cloud transformation initiatives in some of the world’s largest, most complex enterprises. Find out how our Advisory Services will help you build momentum towards transformational outcomes by clicking here.