03.05 Rolling 8-Week PSI Production-Sales-Inventory Balance Sheet (With Dynamic Ramp-Up Yield Conversion)
Governance metadata | Owner: Head of Supply Chain | Last reviewed: 2026-10-22 | Next review: 2027-01-31
Tool positioning: PSI (Production / Sales / Inventory, the production-sales-inventory balance sheet) is the core weapon of the hardware GTM operator for preventing "stockouts that lose ranking" and "unsold dead inventory".
1. Rolling 8-Week PSI Balance Forecast Model (Real Case Calculation / Unit: Units)
Balance identity: ending balance = beginning stock + this week's inbound − this week's sales; and each period's beginning stock = the previous period's ending balance. The example below strictly satisfies this chain and can be recomputed column by column.
| Production-sales metric line item / Week | W1 (current week) | W2 | W3 (alert week) | W4 (inbound week) | W5 | W6 | W7 (stockout week) | W8 (bulk inbound) |
|---|---|---|---|---|---|---|---|---|
| [A] Beginning available stock (Beginning Stock) | 1,200 | 950 | 680 | 590 | 1,280 | 960 | 620 | 260 |
| [B] (+) Bulk production inbound this week (Production In) | 0 | 0 | 200 (by air) | 1,000 (slow vessel) | 0 | 0 | 0 | 1,300 (fast vessel + air) |
| [C] (-) Forecast sales volume (Sales Forecast) | 250 | 270 | 290 | 310 | 320 | 340 | 360 | 380 |
| [D] (=) Ending balance stock (A+B-C) | 950 | 680 | 590 | 1,280 | 960 | 620 | 260 | 1,180 |
| [E] Weighted daily sales velocity (Velocity) | 35 | 38 | 41 | 44 | 45 | 48 | 51 | 54 |
| [F] Days of supply DOS (D/E) | 27 days (tight) | 18 days (stockout) | 14 days (stockout) | 29 days (tight) | 21 days (tight) | 13 days (stockout) | 5 days (critical) | 22 days (tight) |
| [G] In-transit logistics tracking (In-Transit) | 1000 units on slow vessel in transit | 200 units shipped by air | Air shipment received into warehouse and shelved | Slow vessel arrived at port and shelved | Second batch in production | Fast vessel + air shipment dispatched | Customs clearance at port | All received into warehouse and shelved |
| [H] GTM coordination decision (Action Plan) | Keep monitoring the slow vessel | DOS about to drop below 20, urgently air-freight 200 units | Air shipment arrives to relieve the emergency, gap narrows | Bulk units shelved; DOS back to 29 days (warning band) | Start second-batch mass production material preparation | Add 300 units by air freight into the W8 batch; issue third-batch production PO | Critical level: throttle sales-side promotions, protect against stockouts | Merge the batch of 1,300 units into the warehouse; DOS back to 22 days (out of stockout, still in the warning band) |
Aligned with the DOS bands in 00.02 / 01.13: the library uses "45~75 days healthy / 20~45 or 75~110 warning / <20 or >110 critical". This table simulates the pre-launch stocking ramp: goods are just arriving and sell-through is still climbing, so DOS naturally sits below the steady-state healthy band. All eight weeks therefore land in "tight" or "stockout" — which is exactly what the metric should be flagging. W4 (1,000 units in) lifting from 14 to 29 days means "out of stockout, back into warning", not "back to healthy". Steady-state operations should be managed at 45~75 days.
Week-by-week self-check (recomputable): W1: 1200+0−250=950 ➔ W2: 950+0−270=680 ➔ W3: 680+200−290=590 ➔ W4: 590+1000−310=1280 ➔ W5: 1280−320=960 ➔ W6: 960−340=620 ➔ W7: 620−360=260 ➔ W8: 260+1300−380=1180. The chain has no break.
2. Blank, Copy-Ready Standard PSI Calculation Template
### Rolling 8-Week PSI Production-Sales-Inventory Balance Worksheet (Template)
| Production-sales-inventory accounting line item / Period | W+1 | W+2 | W+3 | W+4 | W+5 | W+6 | W+7 | W+8 |
| :--- | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
| **[A] Beginning on-hand stock (Beginning Stock)** | [value] | =last week D | =last week D | =last week D | =last week D | =last week D | =last week D | =last week D |
| **[B] (+) Planned arrival inbound quantity (PO In)** | [value] | [value] | [value] | [value] | [value] | [value] | [value] | [value] |
| **[C] (-) Channel forecast sales volume (Sales Plan)**| [value] | [value] | [value] | [value] | [value] | [value] | [value] | [value] |
| **[D] (=) Ending balance stock (A + B - C)** | =[formula]| =[formula]| =[formula]| =[formula]| =[formula]| =[formula]| =[formula]| =[formula]|
| **[E] Weighted daily sales (Weighted Daily)** | [value] | [value] | [value] | [value] | [value] | [value] | [value] | [value] |
| **[F] Days of supply DOS (D / E)** | **[days]**| **[days]**| **[days]**| **[days]**| **[days]**| **[days]**| **[days]**| **[days]**|
| **[G] In-transit logistics tracking (In-Transit)** | [sea/air] | [sea/air] | [sea/air] | [sea/air] | [sea/air] | [sea/air] | [sea/air] | [sea/air] |
| **[H] GTM decision and replenishment action** | [normal/expedited] | [normal/expedited] | [normal/expedited] | [normal/expedited] | [normal/expedited] | [normal/expedited] | [normal/expedited] | [normal/expedited] |3. Three Core PSI Operating Disciplines (SOP)
- Fixed Monday update: Every Monday before 10:00, channel sales rolls forward and revises the next 8 weeks of forecast based on last week's actual Sell-Out.
- Deviation penalty alert: When the sales forecast deviation rate exceeds ±25%, a cross-functional dedicated post-mortem review meeting is triggered.
- Air freight approval authority: The emergency air freight premium caused by forecast errors is absorbed as a budget deduction by the corresponding responsible business line.
4. Production Line Ramp-Up Yield Loss and Dynamic Effective Inbound Quantity Conversion Model
During the ramp from pilot production (Pilot Run / PVT) to scale mass production (Mass Production) in hardware manufacturing, the factory's scheduled work order quantity and the effective sellable inbound quantity (Available In-Stock) finally arriving at overseas warehouses differ through dynamic shrinkage. If the GTM operator plans on an ideal 100% yield, sellable inventory during the first sales period will be severely overstated.
1. Effective inbound conversion principles and stage baselines
Effective inbound calculation logic:
Actual sellable inbound quantity = factory production work order quantity × line yield (Yield) × (1 - outgoing inspection defect rate) × (1 - cross-border transit loss rate).Line yield stage baselines (Yield):
- PVT pilot readiness phase (aligned with the 01.09 GR3 Market-Readiness Gate gate): the line yield threshold must reach >95% before units are released for shipment;
- MP first-sales ramp phase (aligned with 01.10 GR4 Market-Operations Gate operations): yield steadily improves to 96% ~ 98%;
- Mature steady state: yield is stably maintained at ≥98.5%.
Outgoing inspection and logistics loss: OQC sampling defect rates at outgoing inspection are usually kept within 0.5%; ocean container breakage in transit is kept within 0.2% ~ 0.3%.
2. Worked Example of Loss Conversion for a 1,000-Unit First Batch (AstroNext Primary Case)
| Process stage | Plan and loss parameters | Deduction calculation | Cumulative qualified available units | GTM closed-loop notes |
|---|---|---|---|---|
| 1. Planned production work order (PO Input) | Factory issues the production work order | Initially issued for 1,060 units | 1,060 units | Anticipates pilot and ramp-up losses; material preparation issued at 106% overage |
| 2. First-batch line yield (Yield @95%) | First-batch pilot ramp-up yield 95% | 1060 × 0.95 = 1007 | 1,007 units | The 53 units are losses from line tuning, SMT cold joints, or cosmetic scratches |
| 3. Outgoing inspection loss (OQC Defect) | Outgoing sampling defect rate 0.5% | 5 units removed from 1,007 units | 1,002 units | The 5 units with minor blemishes are converted into after-sales test units or internal engineering samples |
| 4. Cross-border transit (Transit) | Ocean container cargo damage rate 0.2% | 2 units lost from 1,002 units | 1,000 units | The 2 units had outer packaging deformed by moisture; entered the after-sales spare parts bin |
| 5. Final effective FBA shelving inbound | Reaches sellable state (Available) | Effective inbound 1,000 units | 1,000 units | Strictly locks the locked-quantity baseline of 01.08 GR2 Tooling Lock Gate and the first-batch sellable inventory of 01.09 GR3 Market-Readiness Gate |
5. Field Countermeasure: Separating Real PSI Capacity from Fake — MES Real Station Data and Aging Room Photo Verification
In real supply chain negotiations, the "rolling 8-week PSI production schedule" the contract manufacturer hands to the brand is often severely "all good news, no bad news" or "an empty promise dressed up as a plan". When the factory is simultaneously taking on surge orders from major OEMs such as Apple or Xiaomi, it easily and quietly pulls line workers away, severely squeezing the brand's capacity, while the Excel schedule handed to the GTM operator still maintains the illusion — until, on the eve of the mega-promo, the goods cannot ship and the air freight operation blows up.
1. Three Elements of Penetrating Physical Verification
- Element 1: Real MES test station pass-through data (Test Station Count): Do not look at assembly line WIP reports; take the timestamp data automatically uploaded by the test computers at the final test station (FT/RF testing) as the source of truth, eliminating manual Excel tampering;
- Element 2: Daily aging room (Aging Room) watermarked physical photos: Hardware products must undergo 4~8 hours of powered high/low temperature aging. Require the contract manufacturer, before the end of every day shift and every night shift, to have the factory manager hold a camera stamped with that day's Beijing time, photograph fully loaded powered aging racks, and send the photos to the coordination group; if the physical units actually running cannot be seen, that day's output report is directly zeroed out;
- Element 3: Sealed arrival verification of main chip materials: Use the actual physical arrival, unpacking, and scan count of high-lead-time controller chips (SoC/MCU) as the rigid constraint on the production schedule capacity ceiling, eliminating "scheduling production with no chips".
Execution Checklist
These are the self-check items for the key actions in this chapter; tick them off and note the owner and completion date once done.
- [ ] Balance identity verified: week-end stock = opening + inbound - sales, and each week's opening equals the prior week's close
- [ ] DOS band applied correctly: thresholds referenced from 00.02 section 5, not redefined here
- [ ] Effective inbound converted: work order x line yield x (1 - OQC defect) x (1 - transit loss), not the PO quantity treated as sellable
- [ ] Ramp yields taken by stage: PVT / MP ramp / mature steady state differ; one figure is not used throughout
- [ ] MES data verified directly: final test station counts and aging-room watermarked photos, not assembly-line reports
- [ ] Replenishment triggers written: air/express action on stockout band, promotion on overstock band, each with an owner
- [ ] Template fields complete: the blank template's rows A~H are all present and directly copyable