Iterating the 6 Rs
migration strategy selection

At this stage, we recommend that you iterate and evolve the 6 Rs decision tree.
The Determining the R type for
migration section introduced a default decision tree. We recommend revising
the tree, considering the learnings throughout migration of the initial pilot
applications, and ensuring that it still aligns to business drivers, prioritization
criteria, and your unique circumstances. Validate the decision tree with sample
applications, and verify that it still produces the expected strategy. Otherwise, update
the logic accordingly. The resulting tree will be key in establishing baselines for the
portfolio of applications and in allocating migration strategies for each application
component.

As described in the previous 6 Rs
section, the 6 Rs also apply to infrastructure, and it is equally important to
assign them accordingly. While a given application component will have a migration
strategy, at an infrastructure level, each infrastructure asset will follow a given
migration strategy that might be different from the strategy established for the
application component it supports.

Remember that the 6 Rs decision tree applies to application components only. The
migration strategy for infrastructure is derived from the strategy chosen for the
application. For example, for an application component that will be replatformed, the
current infrastructure that hosts it could be retired.

Ensure that migration strategies are allocated to each application component and its
associated infrastructure. This information will be a key factor when estimating effort,
capacity, and skills needed, and when creating migration wave plans.

For more information about determining your 6 Rs, see the AWS Migration Hub strategy recommendations.