Move Field

Goal

Each field belongs to the class that owns its lifecycle; cross-class reaching disappears.

Before the refactoring

class Customer { plan; discountRate; }

After the refactoring

class Plan     { discountRate; }
class Customer { plan; /* discountRate accessed via plan */ }

Savings

Class boundaries align with data ownership; mutations are local; refactoring becomes safer.

Note

Moving a field disturbs every reader — refactor in tooling-supported steps and add a temporary accessor on the original class while migrating.