Refactoring while preserving behavior

Improve internal software structure in small steps while preserving observable behavior.

Method · Technology and product

Core concepts

• Behavior preservation: separate feature changes from structural changes
• Small steps: keep the cause of each change traceable
• Regression checks: verify existing contracts remain intact

Application

Use this approach to reduce the cost of understanding frequently changed code or prepare its structure for a new feature.

Limitations and jurisdiction

Preservation is difficult to judge when observable behavior and tests are unclear. Refactoring is not synonymous with a large rewrite.

Editorial perspectives

• Incremental improvement: tidy the area around a necessary change.
• Preparation: address areas where repeated changes are costly.

Sources

Martin Fowler · Author definition page

Context: International reference; verify the application environment

Source checked: 2026-10-07

Independent editorial summary and source link; the original text is not republished.

Related personas

Translation status

Editorial English translation of the Korean edition. No professional translation or occupational expert review has been completed. Translation does not change the source jurisdiction.

Translation prepared: 2026-10-08 · Source fingerprint: kb-2c59c48839935b18

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