The Replatform migration approach, also known as “lift, tinker, and shift” or “lift and reshape,” involves transferring an application to the cloud while introducing optimisations to enhance its efficiency, reduce costs, or leverage cloud capabilities. For example, you might choose to replatform a Microsoft SQL Server database to Amazon RDS for SQL Server.

Common scenarios where the replatform migration strategy is suitable include:

Transitioning to Fully Managed or Serverless Services: Replatforming allows you to move to fully managed or serverless services in the AWS Cloud, saving time and reducing costs.

Enhancing Security and Compliance: Upgrading the operating system to the latest version can improve security and compliance. For instance, the End-of-Support Migration Program (EMP) for Windows Server can migrate legacy Windows Server applications to supported versions on AWS without code changes. Cost Reduction with AWS Graviton Processors: Utilizing custom-built AWS Graviton Processors can lower costs.

Moving from Windows to Linux: You can reduce costs by migrating from a Microsoft Windows operating system to a Linux operating system. Porting .NET Framework applications to .NET Core, compatible with Linux, is facilitated by tools like Porting Assistant for .NET.

Containerisation for Performance Improvement: Migrating virtual machines into containers without code changes can boost performance. Tools like the AWS App2Container migration tool enables the modernisation of .NET and Java applications into containerized versions.

Replatforming ensures the continued operation of legacy applications while benefiting from security, efficiency, and cost improvements. It offers an intermediary step between basic rehosting (lift and shift) and more extensive refactoring. Of the seven migration strategies, replatforming is often chosen when organisations seek tangible advantages without introducing major new functionality or altering the fundamental architecture significantly.

Benefits of Replatforming:

  • From a technological perspective, replatforming grants applications access to cloud-native functionalities such as auto-scaling, managed storage, and data processing.
  • From a business viewpoint, replatforming is generally more cost-effective than refactoring because it doesn’t necessitate a major development project. It allows organisations to start small and gradually expand their cloud presence.
  • Business outcomes associated with replatforming can include cost reduction, improved performance and reliability for a better customer experience, and accelerated time-to-market for new features.

Risks of Replatforming:

While replatforming can offer substantial benefits, there are risks considering:

  • Limited Automation Benefits: If the application still requires significant manual management after replatforming, the automation advantages may be limited.
  • Scope Creep: Replatforming projects can inadvertently expand beyond their intended scope, moving closer to refactoring. Staying focused on cloud-native components and avoiding unnecessary changes is crucial.
  • Ongoing Costs: Replatforming typically involves ongoing costs associated with cloud services and management. Organisations must budget accordingly.

When to Choose Replatforming:

The decision to replatform should involve a thorough evaluation of the existing application, its architecture, compatibility with the target platform, and alignment with business requirements


The repurchase strategy, also recognized as the “drop and shop” approach, involves substituting an existing application with an alternative version or product that delivers greater business value. Repurchasing typically results in cost reductions related to maintenance, infrastructure, and licensing.

Common scenarios for implementing the repurchase migration strategy include:

Transitioning from Traditional Licensing to SaaS

Shifting from traditional licensing to Software as a Service (SaaS) removes the responsibility of managing infrastructure and addresses licensing concerns.

Upgrading to New Versions or Third-Party Equivalents

Substituting an existing on-premises application with the latest version or a comparable third-party solution in the cloud facilitates the adoption of new features.

Replacing Custom Applications

Instead of recoding or re-architecting a custom application, organizations can choose to repurchase a vendor-based SaaS or cloud-based application.

Before finalising a purchase decision, it is crucial to assess the application based on business requirements, particularly in terms of security and compliance.

After acquiring the new application, the subsequent steps typically include:

  • Providing training to the team and users on the new system.
  • Migrating data to the newly acquired application.
  • Integrating the application into authentication services, such as Microsoft Active Directory, for centralised authentication.
  • Configuring networking to ensure secure communication among the purchased application, users, and infrastructure.

AC3 can provide assistance with these activities to facilitate a seamless transition.

Repurchasing involves the replacement of an existing on-premises legacy application with a Software as a Service (SaaS) solution, colloquially known as the “drop and shop” method. In this process, organisations no longer retain the application in-house but instead acquire data and services from a vendor offering SaaS solutions.

Benefits of Repurchasing:

  • Scalability and Swift Configuration: SaaS solutions are often quick to set up and configure, enabling organisations to benefit from new capabilities to accommodate changing user demands.
  • Automatic Maintenance and Upgrades: Vendors handle maintenance, upgrades, and security patches for SaaS applications, reducing the organisation’s operational burden.
  • Lower Upfront Cost, Flexibility and Choice: Organisations can explore various SaaS options to find the service that best suits their needs, and switching between solutions is generally easier than migrating on-premises applications.

Considerations for a Smooth Transition:

When pursuing repurchasing as a migration strategy, consider the following aspects to ensure a smooth transition:

  • Migration Path: For applications from the same vendor, the migration path may be straightforward, with automated processes for data and user migration. However, new versions of the application may introduce changes in user experience and functionality, necessitating training and adaptation.
  • Legacy Application Maintenance: Ensure that any legacy applications or components related to the original on-premises application are properly retired or replaced.
  • Assessing Legacy Versions: Assess the compatibility of your existing on-premises application with the SaaS version you plan to repurchase. Older versions may require additional effort to migrate or may not be supported.

Repurchasing Use Cases:

Repurchasing is often suitable for standard business applications that support common business functions across industries. These applications are typically part of the core IT landscape for many organisations, making them good candidates for transitioning to SaaS solutions.


Refactoring, also known as re-architecting, is a cloud migration strategy that involves moving an application to the cloud with significant architectural changes to leverage cloud-native features, enhancing agility, performance, scalability, and cost efficiency.

Common use cases include legacy mainframe applications facing limitations, monolithic applications impeding quick product delivery, and legacy applications with limited maintenance. Refactoring is also beneficial for improving testing and quality, addressing issues like poor test coverage.

Benefits of refactoring during cloud migration include cloud-native optimisation, scalability, cost efficiency, and improved quality assurance. However, it comes with potential risks such as high complexity, cost, resource requirements, and careful data migration considerations.

Refactoring is particularly suitable when organisations aim to maximise cloud benefits, especially when legacy applications hinder business agility, scale, or cost efficiency.


To summarise, selecting the appropriate migration strategy for your organisation’s cloud journey is a pivotal decision that must align with your business goals, current infrastructure, and technical capabilities. Whether you choose rehosting, replatforming, repurchasing, refactoring, retiring, retaining, or relocating, each strategy presents unique advantages and considerations.

Ultimately, the decision on the migration strategy should stem from a comprehensive evaluation of your organisation’s specific needs, objectives, and constraints. Diligent planning and execution are essential for a successful cloud migration that optimises the benefits of the cloud while minimising disruptions and risks.