Published: 03 July 2012
Summary
The CIO issues a simple directive: "Move some applications to the cloud." To do this, architects face bewildering choices. In this Decision Point, Richard Watson steers architects to a choice from among five alternatives: rehost on IaaS, refactor using IaaS and PaaS, revise for IaaS or PaaS, rebuild on PaaS, or replace with SaaS. The decision must consider an organization's requirements, evaluation criteria, and architecture principles. However, no alternative offers a silver bullet: All alternatives require architects to understand application migration from multiple perspectives and criteria, such as IT staff skills, existing investments, and application architecture.
Included in Full Research
- Business Scenario
- Architectural Context
- Related Decisions
- Requirements and Constraints
- Migration Goals and Priorities
- Legacy Application Characteristics
- Modernization Requirements
- Application Platform and Architecture Principles
- Development and Operations Skills Constraints
- Migration Cost Considerations
- Principles
- Rehost
- Refactor
- Revise
- Rebuild
- Replace
- Comparing Alternatives
- Distinguishing Products from Services
- Progress on Portability Standards
- Evolution of Cloud Business Models
- Incumbent Platform Players Will Wake Up
- Pre-Decision Assumptions
- Assumption 1: Quality of Service Risks
- Assumption 2: IT Portfolio Management Frameworks
- Using the Decision Tools
- Decision Filters
- Migration Goals Assessment Tool
- Use Rehost
- Use Refactor
- Use Revise
- Use Rebuild
- Use Replace