# Class 11: Supply Chain Resilience (⏰)
*Aug 7, 2025 | [Transcript](./🦦/11⏰2RS_15778_intro_ops_otter_ai.md)*
## 🎯 Teaching Arc
**Hook**: "Nokia survived, Ericsson failed - same fire, different outcomes"
**Puzzle**: Phillips semiconductor fire affected both - why different impacts?
**Resolution**: ⭐️Time to survive > Time to recovery = survive
**Model**: Impact × Recovery Time × Probability (order by PI when TTS>TTR)
## 🗣️ Quality Participation
**[Student]**: "Alternative suppliers matter"
- Prof: "I like where your head's at"
- Impact: Led to multi-sourcing discussion
**Key Discussion**: ⭐️HIGH IMPACT, NO MONEY suppliers
- Prof: "Exactly - low-cost suppliers can cripple you"
- Insight: Semiconductor makers = high risk despite low spend
## 📊 Quick Scores
**Track professor's cues**: "exactly", "I like that", "good point"
**Focus on**: Students who identify non-obvious risks
## 🔗 421 Diagram
### Nokia's Resilience
```
🟢 Supply visibility 🟣 Continuity need
Multi-sourcing Reliability
\ /
Coordinate ←→ Compel
/ \
🟠 Min disruption 🔴 Stable supply
Quick recovery Customer trust
```
### Risk Framework
```
🟢 Map suppliers 🟣 Business continuity
Know TTR Zero disruption
\ /
Coordinate ←→ Compel
/ \
🟠 ⭐️Assume recovery 🔴 Risk transparency
Invest flexibility Supply assurance
```
## 📚 Exam Essentials
**Concepts**:
- ⭐️Proactive (map TTR, TTS, PI) > Reactive (culture)
- Focus on high impact + low visibility suppliers
- Design flexibility where it matters
**Strategy**:
1. Map impact as function of recovery time
2. When TTS < TTR → invest in flexibility
3. Order interventions by probability × impact
**Key Table**: Product/Supplier matrix showing safety stock duration
**Traps**:
❌"Focus on high-spend suppliers"
✅"Map by impact, not spend"
## 🎓 Recitation Points
- "2015 data revealed low-cost = high-risk suppliers"
- "Nokia's advantage: knew suppliers' suppliers"
- "Resilience investment: where TTS < TTR"
- ⭐️"Underestimate negative tail, overestimate positive tail"
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