Phases of a large migration
AWS segments the large migration process into three sequential phases:
Assess phase – You build the business case for the migration.
Mobilize phase – You prepare the organization and mobilize the resources needed for the
migration.
Migrate and modernize – You use your strategy, plan, and
the best practices to migrate and modernize. In this phase, migration is divided into two stages,
initialize and implement.
Strategies for migration
When migrating applications to the cloud, six of the most common migration strategies that you can implement are:
Rehosting also known as “lift-and-shift” involves moving applications without changes.
In the scenario of a large legacy migration, in which the company is looking to implement its migration and scale quickly to meet a business case, the majority of applications are rehosted.
Replatforming, also known as “lift, tinker, and shift,” involves making a few cloud optimizations to realize a tangible benefit. Optimization is achieved without changing the core architecture of the application.
Refactoring (also known as re-architecting) involves reimagining how an application is architected and developed by using cloud-native features. Refactoring is driven by a strong business need to add features, scale, or performance that would otherwise be difficult to achieve in the application’s existing environment.
Repurchasing involves moving from a traditional license to a software-as-a-service model.
For example, a business might choose to implement the repurchasing strategy by migrating from a customer relationship management (CRM) system to Salesforce.com.
Retaining consists of keeping applications that are critical for the business in the source environment. This might include applications that require major refactoring before they can be migrated, or, work that can be postponed until a later time.
Retiring is the process of removing applications that are no longer needed.
Tools and services
- AWS Migration Hub
- AWS Application Discovery Service
- AWS Migration Pattern Library
- Cloud Endure Migration
- AWS Data Migration Service