What is AWS Migration Assessment? How to proceed from current situation analysis to planning and tools to use

"Assessment" is an important process that must be undertaken first in order to successfully migrate to Amazon Web Services (AWS). If you proceed with the migration without accurately understanding the configuration, dependencies, costs, and risks of your current system, you are likely to encounter problems such as design rework, increased costs, and extended downtime.

AWS offers a range of dedicated tools to support assessments, including Migration Readiness Assessment (MRA), Migration Evaluator, and Application Discovery Service. Utilizing these tools allows you to accurately determine the appropriateness of migration, select the optimal migration method, and develop a plan that takes into account the return on investment.

This article provides a systematic explanation of the purpose of AWS migration assessment, the specific steps to take, how to use official AWS tools, and key points to consider when formulating a plan.

What is an AWS Migration Assessment?

An AWS migration assessment is an initial process to safely migrate to AWS. By accurately understanding the state of your current system and organizing the migration method, costs, and risks, you can reduce uncertainty during the planning stage. We will explain the purpose of the assessment and the benefits you can gain by conducting it.

Assessment purpose

AWS migration assessment is a process to "correctly understand the current situation and lay the foundation for determining the migration policy" before creating a migration plan.

First, we will verify from a technical standpoint whether servers and applications can be migrated to AWS. Next, we will estimate the costs of migrating to AWS and understand the differences from the current environment. We will also identify risks such as downtime and dependencies and determine the impact of the migration.

We then gather the information you need to decide whether re-hosting, re-platforming, or re-architecting is the best option, and solidify the direction of your plan. Organizing the necessary information will help you avoid rework during the implementation phase and ensure the entire migration goes smoothly.

Benefits of conducting an assessment

By conducting an assessment in advance, you can create a migration plan based on data, not intuition. The results of organizing the current environment can be shared among stakeholders, preventing misunderstandings and discrepancies in judgment.

In addition, it becomes easier to forecast operational costs after migrating to AWS, which improves the accuracy of budget planning. It also clarifies decisions such as whether to conduct a PoC or migrate in stages, reducing risks during the implementation phase.

How to proceed with the assessment

AWS migration assessment is a process that improves the accuracy and feasibility of the plan by proceeding step by step from organizing the current environment to selecting a method, calculating costs, evaluating risks, and formulating a roadmap.

We will divide the general assessment process into six steps and organize the key points that need to be kept in mind in practice.

1. Inventory of current systems

We organize servers, applications, databases, network configurations, and dependencies. We also identify elements that are likely to become constraints during migration, such as legacy OS and dedicated devices.

2. Current technical and operational status assessment

Next, we visualize the current state of technical and operational aspects, such as availability, security, and operational structure. We also check for gaps with required requirements, such as SLAs, monitoring, and backups.

3. Consideration of migration method

Considering the characteristics of the current environment, we will consider whether re-hosting (lift and shift), re-platforming, or re-architecting (modernizing) is appropriate. We will compare the advantages and disadvantages of each method and make a decision based on both technical and business requirements.

4. Cost Estimation and TCO Comparison

We compare costs between on-premises environments, other cloud services, and AWS to estimate TCO (total cost of ownership). We also evaluate the optimal pricing model, including the potential use of Savings Plans, Amazon EC2 Reserved Instances, and AWS Graviton.

5. Risk analysis and migration difficulty assessment

We assess the difficulty of the migration by sorting out network restrictions, acceptable downtime, business interruption risks, etc. We also check whether existing licenses, such as Windows and commercial databases, can be migrated.

6. Migration Planning and Roadmapping

Finally, decide whether to adopt a phased or all-at-once migration and define the scope of the PoC. Then, set milestones such as inventory → design → migration → cutover, and organize them into an executable roadmap.

Assessment using official AWS tools

AWS provides official tools to help you conduct accurate and efficient pre-migration analysis, allowing you to consistently perform everything from visualizing your current environment to cost assessment and identifying design issues.

Migration Readiness Assessment (MRA)

The Migration Readiness Assessment (MRA) is an assessment program designed to confirm the extent to which an entire organization is prepared for AWS migration. It checks readiness from six perspectives, including People, Operations, and Security, and visualizes migration maturity. It helps organizations understand areas where they are lacking and determine where they need improvement.

Migration Evaluator (formerly TSO Logic)

Migration Evaluator is a tool that visualizes the costs of your existing environment and simulates the costs after migrating to AWS. It proposes the optimal AWS configuration based on actual data such as server specifications and usage status, allowing you to quantitatively confirm the cost-effectiveness after migration. It can also be used for TCO comparisons, providing evidence to support investment decisions.

AWS Application Discovery Service

The AWS Application Discovery Service is a service that automatically collects server information, dependencies, and usage status from on-premises environments. By understanding the connections between applications, it can be used to determine the order of migration and design a phased migration. This tool is particularly effective for companies with complex systems.

AWS Well-Architected Framework Review

The AWS Well-Architected Framework Review is a framework for systematically identifying design issues. It allows you to verify whether the post-migration architecture is appropriate from the perspectives of reliability, security, operational efficiency, cost optimization, etc. The assessment results help you clarify areas for improvement and ensure the architecture is durable for future operations.

Migration method and configuration image to be defined after assessment

Based on the information obtained from the assessment, we will specify the migration method and configuration pattern. We will organize multiple perspectives, such as business requirements, technical constraints, and costs, and select the most realistic and effective migration approach.

How to choose a migration method

When deciding on a migration method, consider the following points:

• Business impact: Confirm your tolerance for downtime due to the migration and the extent of the impact on your business.

• Technical constraints: We take into consideration technical constraints that are difficult to change, such as legacy operating systems and commercial licenses.

• Operational structure: We will determine whether to migrate in stages or all at once based on the structure and skill level of the team responsible for AWS operations.

• Cost/ROI: Compare the migration costs and benefits (reduced operations, improved availability, etc.) and select the method with the highest return on investment.

Typical configuration pattern example

The following configuration patterns are often adopted as a migration method after assessment:

• Lift and Shift + Operational Improvement

  • This is a pattern where you re-host to AWS and then improve operations using CloudWatch, AWS Systems Manager, etc. This is suitable for projects with limited timeframes or when you want to prioritize cloud migration first.

• Incremental modernization

  • This method involves migrating to AWS once and then gradually refactoring to Amazon RDS, Amazon ECS, AWS Lambda, etc. This makes it easy to reduce downtime and achieve cloud-native migration while minimizing the impact on business operations.

• Moving to Full Cloud Native

  • This is a pattern in which the architecture is completely modernized at the same time as migration, and a shift to microservices and serverless is promoted. It is adopted when prioritizing long-term operational efficiency and improved availability, or in projects that are close to new development.

It is common to employ these patterns alone or in combination depending on the level of improvement required and business requirements.

Common issues and mistakes in assessment

If the assessment is carried out incorrectly, it will affect the entire plan. Here we will summarize the issues that frequently arise in practice and the background to them.

Insufficient inventory makes dependencies invisible

If the dependencies between servers, applications, and databases are not properly understood, the switchover order for each migration target cannot be determined, which can result in prolonged downtime.In environments where configuration management is carried out manually, it is easy to miss things, so it is important to use tools such as the AWS Application Discovery Service to accurately collect information.

Unable to grasp the exact cost of on-premise assets

If you create a migration plan without understanding the actual costs of your current environment, you will not be able to properly evaluate the cost-effectiveness of migrating to AWS. You can make an accurate decision by organizing direct and indirect costs such as hardware purchase costs, maintenance costs, and labor costs, and using Migration Evaluator to compare the TCO with AWS.

Planning is carried out with differing assumptions among stakeholders

If assumptions such as the scope of migration, downtime tolerance, and cost sensitivity are not shared among teams, misunderstandings will surface during the design and migration preparation stages, resulting in rework. It is effective to use a Migration Readiness Assessment (MRA) to organize the plan while ensuring organizational agreement.

Insufficient consideration of post-migration operations led to rework

If you prioritize the migration itself and don't fully consider post-migration monitoring, backup, and security operations, additional work may be required after migrating to AWS, resulting in an increased operational burden. By solidifying your post-migration operational design in advance by referring to the AWS Well-Architected Framework, you can avoid having to go back and do things again.

H2: Summary

AWS migration assessment is the first critical step that determines the success or failure of a migration project. By systematically conducting an inventory of the current environment, technical evaluation, cost estimation, risk analysis, and selection of the migration method, we can create an execution plan without any reversals.

AWS has a range of official assessment support tools, including Migration Readiness Assessment (MRA), Migration Evaluator, and AWS Application Discovery Service, which allow you to formulate plans based on data rather than subjectivity. By utilizing these tools, you can efficiently determine the suitability of migration, select the optimal method, and consider configuration patterns.

After the assessment, it is also important to clarify the migration method and roadmap and align the prerequisites among stakeholders. Insufficient inventory, inadequate cost understanding, and plans that do not take post-migration operations into consideration can lead to rework and cost overruns.

By conducting a thorough assessment and combining it with official AWS tools and best practices, we can reduce the risks of your migration project and ensure a safe and steady cloud migration.