In the planning phase that precedes any cloud-migration journey, the question inevitably arises: Which applications should be selected for migration, and why? Start with the six “Rs” of migration outlined below — it’s a proven framework for helping organizations successfully plan and execute high-impact cloud migrations.

retire: throw out old applications

triangle with exclamation point
triangle with exclamation point

Retiring systems and applications might seem like a waste of resources, but there are many instances in which it’s the most appropriate strategy. After all, during the application-discovery process, organizations commonly uncover applications that are no longer in use or have limited applicability. However, these applications and systems should be regarded as candidates for retirement if and only if better cloud-based alternatives are available for their users.

retain: do nothing (at least for now)

Some applications or workloads simply aren’t ideal for the cloud. Examples include applications that are risky yet critical to the business, or those that are unusually complex due to far-reaching interdependencies. Other reasons to retain in-house systems include riding out the depreciation value or avoiding exorbitant costs associated with migration. Retaining some IT applications and systems on-premises is an especially popular option for organizations adopting hybrid-cloud strategies right now.

rehost: move applications to the cloud on an “as-is” basis

three clouds with arrow
three clouds with arrow

In a nutshell, rehosting involves moving your organization’s applications to the cloud on an “as-is'' basis. Perhaps unsurprisingly, given its simplicity, this remains an extremely popular cloud-migration strategy (in business parlance, it’s commonly referred to as a “lift and shift”). And it certainly has its upside, too: It’s quick, for starters, requiring relatively modest changes on the organization’s end. Done right, what’s more, underlying systems and applications can be successfully migrated to the cloud with minimal outlays in terms of cost or effort.

repurchase: replace a legacy application with a cloud-based application

You’re probably familiar with the concept of software as a service (SaaS), which involves taking your existing data and applications, then running them in a cloud-based product to help manage operations. But this could also be framed in more black-and-white terms, since the reality is that you’re essentially replacing a legacy application with a new (but similar) cloud-based application. Human resource, customer relationship management (CRM) and content management (CMS) applications are among the most frequently repurchased at organizations today.

replatform: introduce changes in order to fit new platforms

two puzzle pieces about to fit
two puzzle pieces about to fit

While similar to rehosting, replatforming should nonetheless be bucketed in an altogether different category. After all, even if it doesn’t require critical changes to your application’s core architecture, it does entail making modifications elsewhere.

For example, replatforming might mean that you have to plug your application into a new cloud-based database system, or switch your web server from a proprietary version like Weblogic to an open-source web server like Apache Tomcat. Either way, while replatforming can be costly, it’s often the best option for organizations that are unable — for whatever reason — to restructure monolithic legacy systems during a migration.

refactor: rewrite an application to make it public cloud-friendly

Refactoring entails rewriting either part or all of an application in order to make it public cloud-friendly. And, as such, a quick warning for the weary: Refactoring typically requires extensive changes, not the least of which is the reengineering of system- or application-level logic so that you can leverage all available cloud features.

The upside, on the other hand, is pretty huge: After refactoring, applications and systems can be fully optimized to utilize cloud-native features. As a result, even if the cost and effort of refactoring are high at first, over the long haul this approach often proves not only efficient but cost-effective as well. At the end of the day, after all, your application will be comprehensively reengineered to take advantage of cloud-native features.

key takeaways

Correctly selecting and prioritizing applications in advance of a cloud migration can be a key factor in determining both the short- and long-term success of the endeavor. The six “Rs” identified above should help you think through your options, understand the associated risks and rewards and execute accordingly. At the same time, of course, you should first make sure that everyone on your team clearly understands what’s behind your cloud migration in the first place — but more on that here.

Looking for more in-depth guidance on successful cloud migrations? The latest comprehensive white paper from Randstad has you covered.