The document outlines a comprehensive strategy for migrating applications to the cloud, emphasizing the need for thorough application assessment, prioritization based on business criticality, and selecting appropriate migration models such as rehosting or refactoring. It advocates for a DevOps approach to bridge gaps between development and operations teams and enhance collaboration. The migration roadmap includes steps from discovery to optimization, ensuring a tailored and value-driven migration process.

1. Cloud Strategy
Migrating to the cloud

2. Application Assessment
• Conduct application
discovery workshop(s)
• Interview application
Owners
• Implement tool-based
discovery
• Profile application
inventory
• Identify critical and/or
complex apps
• Priorities apps
• Driven by priority, skills
and best practices
• Capture inter-application
dependencies
• Choose migration model
• Check plan against IT
change and
organisational
management systems
• Focus on new
operational model
Collecting
Application
Portfolio
Define
Priorities
Determine
Application
Migration
Options
Create
Migration
Roadmap

3. Application and data discovery
Collecting Information
• Use AWS and partner tooling to discover
app complexity
• Use cloud best practice guidelines
• Employee work shadowing and discovery
techniques
• Capture sample data flows
• Run work shops with product owners
• Engage the staff who use these
systems
Key information
• App details + technical/business owner
• Infrastructure information (network,
ports/protocols, security, OS, etc.)
• Data information (database(type), data
sensitivity, data exchange)
• App information (frameworks, language, tier
information)
• This will help you discover the application
complexity!
Partner tooling
• Multiple sources but check the AWS Market Place for SaaS offerings

4. Prioritisation
• Business criticality (frequency of use, number of users, effected business processes)
• Consider consequences of failure
• Technology complexity (In house knowledge/skill set, fragility, other dependencies)
• Evaluate probability of failure
• Sizing (Data size, networking requirements, number of servers)
• Determine time of data migration and effort
• Disaster Recovering planning (Contingency planning, operational requirements, data
retention)
• Planning for post migration operations and costs

5. Devops
• Traditionally organisations have split IT with different demands, which has
lead to silo’s of knowledge and slower none progressive IT Infrastructure
• On one hand developers are pushed to innovate and more products forward
• On the other hand Systems Admins are naturally cautious
• They are held responsible for the stability of a system and any issues
that effect users
• Cloud has removed the barriers of slow infrastructure however
organisations now need to bring once separate teams back together and
include both in the progression of the business
This is called DevOps!

6. Migration Model
Application
Assessment
Rehost
Replatform
Repurchase
Refactor
Retire/Retain

7. Migration Options

8. Rehost
• Rehost
– Simple “lift and shift”
– Use automated migration tools
• VMware export
– Manually rebuild systems
• Integrate orchestration tools
– Chef/puppet/cfengine

9. Replatform
• Use the opportunity to improve the
systems
– Migrate/Upgrade OS
– Improve Security
– Improve performance
• Evaluate your collected data to right size your
servers

10. Repurchase
• SaaS (software as a service)
– Runs outside your infrastructure
– Maintained by a third party
• Ensure good SLA’s (service level agreements)
– Reduces overhead of management

11. Refactor/Rebuild
• IaaS or PaaS
– Rebuild the systems in the cloud but consider using
the power of the services on offer
• Adapt the application to use PaaS services
– S3 for storage
– RDS Databases
• Re-code for modern architecture patterns
– Loosely coupled design etc. etc.

12. Retire/Retain
• Is the Application still in use?
– Number of users
– Migrate users to another system
• Will the application be required much longer?
– Evaluate the effort required to move against the
application life cycle

13. Application Migration Roadmap
Strategy Plan Build Run
Initiate Discovery Design Migrate Integrate Validate Operate Optimise
• Business Vision
and Strategy
Review
• Cloud TCO
Assessment
• Cloud
Operations
Education
• Security and
Risk
Assessments
• Current state
Assessment
• Application
Discovery
• Application
Prioritisation
• TCO Detailed
Review
• Infrastructure,
Security and
Governance
Analysis
• Architect
Systems
• AWS/Partner
Review
• Determine
Migration
Pattern
• Select Tooling
• Build migration
plan
• Deploy code in
new
environment
• Conduct Proof
of concepts
• Ready on
premises
systems
• Migrate data
• Functional testing
• Security
hardening
• Scalability tests
• Performance
optimisation
• User Acceptance
Testing
• Transition
• Training
• Service
management
• Governance
Review
• Decommission
Legacy
systems
• Infrastructure
• Operational
• Application
• Data
• User Evaluations
• System
Performance
• Cost optimisation
• AWS Trusted
Advisor
• Continuous
Integration/Deploy
ment

14. AWS Cloud Adoption Framework

15. People and Process

16. Conclusions
• Application Migration can be a process that unites Business and IT and it is
a larger picture than purely technical or business driven
• Use the opportunity to share knowledge and create collaborative
workshops
• Take the opportunity to unite IT and use the “DevOps” approach
• Applications should be assessment should be value driven
• Make sure moving the system benefits all the users and product owners
• Use the opportunity to improve the application and work flow
• Ever application and business use is unique
• Don’t take a generic approach to migration