Solita Cloud Buyer's Guide

6. Six R’s: strategies to move (or not to move) to the cloud

When you decide to move applications to the cloud, you will have to take the inevitable step of migrating your existing applications and data. To make it manageable, there are four different strategies that can help you.

6. Six R’s: strategies to move (or not to move) to the cloud

Depending on how you look at it, there are four or six strategies to move to the cloud. Four or six? Well, the first two are not strategies that will get you into the cloud. They are about retaining (Retain) the infrastructure or discontinuing it (Retire). They have the advantage that no migration needs to take place. And in some cases, that can be the best solution. That leaves us with four possible approaches:

  1. Rehost

    Sometimes called “lift-and-shift”, this approach has the lowest impact. After all, you only move from an on-premises server to the cloud. Nothing else changes. This could result in better resilience, global distribution and scalability. But it also means that you don’t really take advantage of the benefits that the cloud can offer.

  2. Repurchase

    Repurchase goes a step further. You move from one on-premises product to another, often by moving from a traditional license to a SaaS model. When you have a traditional CRM system and choose a SaaS based tool eg. like Salesforce.

  3. Replatform

    In replatforming, you are going to bring an application to the cloud, and while doing so, you are going to take the opportunity to make improvements that are possible thanks to the cloud. For example, you may use CaaS or PaaS instead of virtual machine based containers or databases.

  4. Re-architect

    Re-architecting is sometimes also called refactoring. When rethinking your infrastructure and applications, you start from the assets the cloud has to offer to improve agility, performance, and scalability. Here you separate your application into microservices and try to map these services to cloud native services, such as serverless, batch, caching solutions etc. This allows you to use your infrastructure more efficiently. As a result, you only pay when you use things. The best examples are probably databases. Thanks to eg. serverless, you can easily scale up and take backups without much added cost.

    It should be noted that these four strategies are not in this order by chance. Where rehosting has the least impact and requires the least time and budget, re-architecting is quite different. You start from scratch, so to speak, which requires a lot of time and budget. But the outcomes are systems that are easier and cheaper to maintain and faster to release new versions.

The steps of cloud migration

Once you decide upon a strategy, you still have to implement it. Step by step is the way to go. Those who want to complete migration as quickly as possible usually need to go back to the drawing board.

Cloud buyer's guide cloud migration

When deciding which migration strategy to follow, a few more elements are important.


The nature of the application is of great importance. In fact, it is a choice between the degree of control and the scale you want. These are opposites: more control means less scale and vice versa. Which choice is the right one depends on each case.

Secondly, also consider your level of ambition and your resources. They too will help determine which strategy you will opt for. Thirdly, it is important to determine your strategy based on each application. Here too, there is no one-size-fits-all, but rather a strategy for each application.

The migration itself is only step 3

Only after you have made these choices can you make your decision. And then it starts. It is best to migrate step by step. Take into account the learning curve that your organization will go through anyway. Perhaps start with a smaller and non-business-critical system to use the learnings of that migration for the larger roll-out. This is the best way to go from the as-is situation to the to-be situation.

The most common mistakes to avoid during a migration are the following:

  • Migrating everything at once. This increases your risks and makes migration very complex. Rather choose a step-by-step approach.
  • Lack of testing phase. Don’t skip testing! Pick-up low hanging fruits that are simple to migrate and applications that are not business critical.
  • Neglecting differences between cloud platforms. Not all the clouds are the same! They have differences, so study what each cloud can provide and choose which are best for your organization.
  • Migrating without business rationale. Migration always needs the “why?”. Don’t migrate if there is no justification for it.
  • Neglecting the human factor. Migration is a transformation project and people need to be involved. The biggest change concerns people.
  • Lack of expertise. Cloud migration may not be easy to do yourself. To mitigate the lack of expertise, use a partner who can help you with migration.