Mastering Application Migration Assessment

This guide covers the critical Assess phase of the AWS migration journey, focusing on the Migration Readiness Assessment (MRA), the 7 Rs migration strategies, and total cost of ownership (TCO) evaluation as defined in the AWS SAP-C02 curriculum.

Learning Objectives

After studying this guide, you should be able to:

• Define the core components of a Migration Readiness Assessment (MRA).
• Categorize applications using the 7 Rs Migration Strategies.
• Utilize AWS Migration Hub and discovery tools for portfolio assessment.
• Evaluate Total Cost of Ownership (TCO) to build a business case for migration.
• Develop a Wave Plan for prioritized workload migration.

Key Terms & Glossary

• MRA (Migration Readiness Assessment): A process based on the AWS Cloud Adoption Framework (CAF) to evaluate an organization's cloud readiness.
• TCO (Total Cost of Ownership): A financial estimate intended to help buyers and owners determine the direct and indirect costs of a product or system.
• 7 Rs: The seven common migration strategies: Retire, Retain, Rehost, Relocate, Replatform, Repurchase, and Refactor.
• Wave Planning: The process of grouping applications into logical "waves" for migration based on dependencies and business priority.
• AWS Migration Hub: A central location to collect inventory and tracking data to provide visibility into the status of migrations.

The "Big Idea"

Migration assessment is not merely a technical inventory; it is a strategic alignment phase. Before a single server is moved, an architect must validate that the migration provides business value, identify gaps in organizational readiness (using the CAF), and select the strategy that balances speed-to-market with long-term cloud optimization.

Formula / Concept Box

Hierarchical Outline

1. The Assessment Phase
   • Portfolio Discovery: Using AWS Application Discovery Service to map dependencies.
   • Financial Assessment: Comparing TCO and calculating ROI.
2. Migration Readiness Assessment (MRA)
   • Evaluating the 6 CAF Perspectives (Business, People, Governance, Platform, Security, Operations).
   • Identifying "Gaps" in skills and infrastructure.
3. Strategy Selection (The 7 Rs)
   • Low Effort: Retire, Retain, Relocate.
   • Medium Effort: Rehost (Lift & Shift), Repurchase (SaaS).
   • High Effort: Replatform (Lift & Reshape), Refactor (Decouple).
4. Wave Planning & Prioritization
   • Creating "Migration Waves" based on low-complexity "quick wins."

Visual Anchors

Migration Assessment Workflow

Effort vs. Optimization Matrix

Definition-Example Pairs

• Relocate: Moving workloads at the hypervisor level without changing the OS or hardware architecture.
  • Example: Moving VMware VMs from an on-premises data center to VMware Cloud on AWS.
• Replatform: Making a few optimizations to achieve a cloud benefit without changing the core code.
  • Example: Moving a self-managed Oracle database to Amazon RDS for Oracle.
• Repurchase: Moving to a different product, typically a SaaS model.
  • Example: Moving from on-premises HR software to a cloud-native SaaS like Workday.

Worked Examples

Scenario: The Legacy Mainframe

Context: An organization identifies a 15-year-old accounting application running on legacy hardware with no current developer support. It is rarely accessed by users.

• Assessment: The MRA identifies a massive "People" gap (no expertise) and "Platform" gap (incompatible hardware).
• Decision: Retire. The cost of migration outweighs any remaining business value.

Scenario: The Web Frontend

Context: A high-traffic web application needs to scale during the holidays. It currently runs on Windows Server 2019 VMs.

• Assessment: TCO shows that scaling on-premises requires over-provisioning hardware that sits idle 90% of the year.
• Decision: Rehost using AWS Application Migration Service (MGN) to gain immediate elasticity, with a future goal of Replatforming to containers (Amazon EKS).

Checkpoint Questions

1. What are the 6 perspectives of the AWS Cloud Adoption Framework (CAF) used in an MRA?
2. Which "R" involves migrating at the hypervisor level, specifically for VMware workloads?
3. In a migration heatmap, what does a Red status indicate?
4. Why might an organization choose to Retain an application instead of migrating it?
5. What tool provides a centralized dashboard to track the status of migrations across multiple AWS tools?

Muddy Points & Cross-Refs

• Rehost vs. Relocate: This is a common exam point. Rehost (Lift & Shift) uses agents to copy the OS/Data to EC2. Relocate transfers the VM state directly between hypervisors (e.g., vMotion to VMware Cloud on AWS).
• TCO Pitfall: Don't forget "Hidden Costs." In-house data centers include costs for security guards, fire suppression, and cooling—all of which are included in the AWS service price.
• Further Study: Review the AWS Cloud Adoption Framework (CAF) 3.0 whitepaper for a deep dive into MRA components.

Comparison Tables

Comparison of Migration Strategies