R1
Rehost
Lift & shift
Move the application to cloud infrastructure with minimal changes: same code, same architecture, just running on cloud VMs.
Best for: apps that work fine but need to move fast, or where code changes carry high risk.
R2
Replatform
Lift, tinker & shift
Targeted optimisations during the move, managed PaaS database, containerised app tier, without changing the core application.
Best for: apps that benefit from managed services but don't need architectural changes.
R3
Refactor
Re-architect
Redesign and rewrite parts of the application to take full advantage of cloud-native capabilities, breaking monoliths into services, adopting APIs.
Best for: apps with high business value constrained by legacy architecture.
R4
Repurchase
Drop & shop
Replace the application entirely with a commercial SaaS product: Salesforce, ServiceNow, Microsoft 365 equivalents.
Best for: commodity applications where buying is more cost-effective than maintaining custom code.
R5
Retain
Keep as-is
Some applications aren't worth migrating right now: compliance constraints, recent investment, end-of-life timeline. Retain and revisit later.
Best for: apps approaching end-of-life, recently rebuilt, or under regulatory holds.
R6
Retire
Decommission
Identify and decommission applications no longer used or superseded: freeing up resources, reducing attack surface, eliminating maintenance burden.
Best for: redundant, duplicate or unused applications consuming resources without delivering value.