プロダクトの移行戦略

You've built a new design system. Great! But what about your existing products and applications? Migrating them is crucial to leverage the full benefits.

• Consistency: Ensure all products look and feel unified.
• Efficiency: Speed up development with reusable components.
• Quality: Improve accessibility, performance, and maintainability.

This lesson explores how to plan and execute these migrations successfully.

Migrating an existing product to a new design system isn't always straightforward. You might encounter:

• Legacy Code: Old, complex codebases that are hard to change.
• Time & Resources: Migration can be a significant undertaking.
• Temporary Inconsistency: Products might look mixed during the transition.
• Team Buy-in: Ensuring everyone understands and supports the change.

Planning is key to overcoming these hurdles.

When moving to a new design system, two primary strategies stand out:

1. The Big Bang Approach: Migrate everything at once.
2. The Incremental Approach: Migrate piece by piece, over time.

Each has its own benefits and drawbacks, and the best choice depends on your project's size, complexity, and risk tolerance.

The Big Bang strategy involves migrating your entire product or application to the new design system in one go. It's like launching a completely new version.

• Pros: Achieves full consistency quickly; avoids temporary mixed UIs.
• Cons: High risk; requires significant upfront effort and coordination; potential for downtime or major bugs.

Best for: Smaller, less complex applications, or when a complete redesign is already planned.

The Incremental strategy involves migrating your product piece by piece, feature by feature, or even component by component, over a period of time.

• Pros: Lower risk; allows for continuous delivery; easier to manage resources; immediate feedback.
• Cons: Can lead to temporary UI inconsistencies; takes longer to achieve full adoption.

Best for: Large, complex, or mission-critical applications where downtime is unacceptable.

Before you start, conduct a thorough audit of your existing product's UI. This means taking inventory of all components and patterns currently in use.

• List all buttons, forms, cards, navigation items.
• Document their current states and variations.
• Identify unique patterns not covered by the new design system.

This audit helps you understand the scope of the migration.

Once you have an inventory, map your existing UI components to the new design system components. This shows you what needs to change.

• Direct Mapping: OldButton → DSButton
• Custom Mapping: OldComplexWidget → combination of DSCard + DSForm
• Gap Analysis: Identify any old components that have no direct equivalent in the new system. These might need new components or redesign.

For incremental migrations, 'wrapper components' are a lifesaver. You can create a wrapper around a new design system component that mimics the old component's API.

This allows you to swap out implementations without rewriting every usage of the old component immediately.

Starting with a 'pilot project' is a smart move. Pick a small, contained part of your application (e.g., a single page, a new feature) and migrate it first.

• This allows your team to learn the new system.
• You can identify unforeseen challenges early.
• It builds confidence and demonstrates value before a full rollout.

Apply lessons learned from the pilot to subsequent phases.

Rigorous testing is non-negotiable during a migration. You need to ensure the new components integrate correctly and don't introduce regressions.

• Visual Regression Testing: Tools to detect unintended visual changes.
• Functional Testing: Ensure features still work as expected.
• Accessibility Testing: Verify compliance with WCAG standards.
• Performance Testing: Check for any slowdowns.

Automate as much of this as possible.

Considering the challenges and benefits, which of these statements correctly describes a characteristic or application of the Incremental Migration Strategy?

Migrating to a new design system is a significant undertaking, but the long-term benefits are immense. Remember these key takeaways:

• Choose between Big Bang (fast, high risk) and Incremental (slow, low risk).
• Always start with a thorough UI audit and component mapping.
• Consider wrapper components for smoother transitions.
• Run pilot projects to learn and iterate.
• Prioritize rigorous testing throughout the process.

Well-planned migration ensures your products fully leverage the design system's power.