Lesson 2: Why Specifications Matter NOW
Three Convergent Forces (2025)
1. AI Production-Readiness
AI coding assistants can now generate production-quality code - but only with clear specifications.
2. Proven Time Savings
Specifications now save time instead of adding overhead:
- Every minute on specs saves 3-5 minutes of iteration
- Positive ROI for the first time in history
3. AI Literal-Mindedness
Unlike humans, AI doesn't infer intent - it executes literal instructions.
Why SDD Succeeds Where MDD Failed
Model-Driven Development (2000s): Failed because code generation was poor
Specification-Driven Development (2025): Succeeds because AI can generate excellent code
Key Takeaway
✅ SDD emerged in 2025 due to AI capabilities
✅ Specs have positive ROI for the first time
✅ AI needs clear boundaries to operate effectively