Simple Design Rules

Guide Java developers through Kent Beck's simple design rules when evaluating design and refactoring choices. This is an interactive SKILL.

What is covered in this Skill?

• Using tests as the first correctness boundary before design cleanup
• Revealing intention and maximizing clarity before abstraction pressure
• Reducing duplication without hiding domain meaning or worsening readability
• Treating fewer elements as the final simplification pressure after correctness, clarity, and duplication
• Comparing Java design and refactoring options with the ordered rules
• Reporting the chosen option, tradeoffs, validation signal, and remaining risk

Constraints

Apply simple design rules in priority order, and do not optimize later rules by weakening earlier rules.