Reorder plan: order 500 units of Product A now and nothing else
That is the supplier minimum, and it costs 4,500, which uses all your cash. A is already below its reorder point. B and C have far more stock than they need.
Assumptions
- Lead time: I used the mean of your last four shipments, 22.75 days, not the 21 days quoted. The standard deviation is 3.5 days, and it is the biggest risk in the plan.
- Service level: 95% for A (z = 1.65).
- Demand: weekly sales from the last 8 weeks, converted to daily. Eight weeks is a short history, and I assumed no seasonality or promotions.
- ABC ranking: I used cost value because you didn't give selling prices.
ABC and dead stock
| SKU | Avg/week | Weekly cost value | Class |
|---|---|---|---|
| A | 148.75 | ~1,339 | A (~80%) |
| B | 21.9 | ~328 | B (~20%) |
| C | 1.25 | ~8 | C (<1%) |
- C dark blue: 120 units (720 at cost) with no sales in 100 days is dead stock. Clear it with a discount or a bundle, and don't reorder it.
- C overall: 540 units is about 430 weeks of supply, or roughly 8 years. Stop buying C and treat the rest as slow clearance.
Per-SKU plan
Product A (order now)
- Daily demand is 21.25 units, with a daily standard deviation of 5.28.
- Demand over the lead time is 21.25 × 22.75 ≈ 483 units.
- Safety stock is 1.65 × √(22.75 × 5.28² + 21.25² × 3.5²) ≈ 130 units.
- Reorder point is 483 + 130 ≈ 613 units. You have 420, so you are below it.
- Cover is 420 / 21.25 ≈ 20 days, which is less than the 22.75-day lead time.
- A order placed today is expected to arrive after you run out, by about 3 days, or roughly 60 units of lost sales. Even a perfect order can't prevent that.
- The ideal order covers the lead time plus a 30-day review period. That is 21.25 × 52.75 + 130 − 420 ≈ 830 units (about 7,470).
- Your cash covers only 500 units. That gives about 23 days of cover once it arrives, so you will need to reorder again very soon.
Product B (don't order)
- Daily demand is 3.1 units. Stock is 310 on hand plus 100 arriving, 410 in total, which is about 131 days of cover.
- Its reorder point is about 87 units, so you won't be near it for months.
- The 200-unit minimum order would only add to the overstock.
Product C (don't order)
- See the dead-stock notes above.
Cash
- The 4,500 goes entirely to A.
- To fund the 330-unit gap (about 2,970), free cash from slow stock. Stock tied up is B at 4,650 (310 units at 15) and C at 3,240 (540 at 6).
- Clearing the dark blue C (720) and part of C's remaining stock is the easiest cash to free. Hold off on B's 100 incoming units only if the supplier allows it.
Risks
- Lead-time variability: at the 27-day worst case, demand over the lead time is about 574 units, so you'd stock out about 7 days before arrival. Ask the supplier about splitting the order, or air-freighting a small top-up (about 60–100 units) to bridge the gap.
- Short history: 8 weeks is a weak basis, and an upswing or a promotion would raise the numbers.
- Supplier terms: confirm the minimum order, payment terms and any freight costs. Freight isn't in the 4,500.
What to measure next
- Actual lead time for each shipment.
- Stockout days for A.
- Weekly forecast error.
- Sell-through of the C clearance.
- Reorder A again as soon as cash allows. Don't wait for the 500 units to arrive.
If you give me selling prices and a freight cost, I can redo the ABC ranking on margin and check whether the 4,500 still buys 500 units.
Real run in an isolated folder with only this skill installed. Only the Skill and Read tools were enabled, so no command was run and no file was written. The store and all numbers are invented and the model had no access to a real store. The lead-time statistics, safety stock and reorder point were recomputed by hand afterwards and matched.
できること
販売履歴と仕入先のリードタイムから、SKU（バリエーションごと）で補充を計画します。ABC 分類を行い、不良在庫を示し、平均需要（欠品日を除く）、選んだサービスレベルに応じた安全在庫、発注点、在庫日数、発注量を計算します。需要のばらつきより大きいことが多いリードタイムのばらつきの影響も含みます。さらに、傾向、季節、販促、新商品、長い海上輸送、資金に合わせて調整し、症状と考えられる原因（よく欠品する、不良在庫、資金繰りが厳しい）を挙げます。
出力
出どころつきの前提、ABC 表と不良在庫リストおよび対応案、SKU ごとの計画（今何を発注するか）、弱い見積もりと計画を変えうる要因、次に測るべきこと。数字つきの計算例が Skill に組み込まれています。
向いている場面
小規模ストアの発注計画、よく欠品する原因の調査、動きの遅い在庫の整理。
低リスク：スクリプトのない指示のみのパッケージで、ネットワーク接続やファイル書き込みはありません。計画は予測でも約束でもありません。需要も納品も不確実で、Skill は目標とするサービスレベルを明記します。仕入先の最小発注数、運賃、通関、保管のルールは、国によって異なり変更されるため、仕入先や運送会社に確認してください。在庫システムは見えず、ご提示の数字だけを使います。AIBars 制作のオリジナル（MIT）。架空の 3 商品のお店で 1 回試用し、統計値は後から手計算で確認しました。