# Class 8: Yedioth Newsvendor Model (π°)
*Aug 1, 2025 | [Transcript](./π¦¦/8nv(π°)15778_intro_ops_otter_ai.md)*
## π― Teaching Arc
**Hook**: "14,000 SKUs, weekly delivery, unpredictable demand"
**Puzzle**: How optimize inventory when demand is censored?
**Resolution**: Pool data + newsvendor model with service levels
**Model**: Q* = β(2DF/H) + safety stock for uncertainty
## π£οΈ Quality Participation
**Joe** β: "Can update Q after first cycle vs online learning"
- Prof: Appreciated complexity awareness
- Impact: βοΈ"Changing Q complicates policy, makes fragile"
**Key Discussion**: Service level trade-offs
- u/(u+o) formula for target service (95%)
- "Hate runout AND hate inventory"
## π Quick Scores
Focus on students who:
- Question model assumptions
- Identify implementation challenges
- Connect theory to practical constraints
## π 421 Diagram
### Yedioth Model
```
π’ Weekly delivery π£ Small retailers
Sales data 14,000 SKUs
\ /
Coordinate ββ Compel
/ \
π Min returns π΄ 95% availability
Reduce waste One-stop shop
```
## π Exam Essentials
**Concepts**:
- Newsvendor with censored demand
- Service level: u/(u+o) where u=underage, o=overage
- Lead time uncertainty (DDLT as random variable)
**EOQ Components**:
- D: Demand rate
- F: Fixed order cost ($500)
- H: Holding cost ($0.45)
- C: Unit cost ($45)
**Strategy**: Pool similar products for better demand estimates
**Traps**:
β"Optimize each SKU separately"
β
"Pool data across similar items"
## π Recitation Points
- βοΈ"Updating Q frequently makes system fragile"
- "5-day lead time adds complexity"
- "Balance stockout cost vs holding cost"
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