Subject: Purchase Order PO-202603-001

Dear [Supplier Contact],

Please find our purchase order details below:

PO Number: PO-202603-001
Order Date: March 12, 2026
Expected Delivery: March 26, 2026

Items:
| SKU | Description | Qty | Unit Cost | Total |
|-----|-------------|-----|-----------|-------|
| YS-1001 | Cotton T-Shirt, White, S | 100 | $8.50 | $850.00 |
| YS-1002 | Cotton T-Shirt, White, M | 150 | $8.50 | $1,275.00 |

Total: $2,125.00
Payment Terms: Net 30

Please confirm receipt of this order and your expected ship date.

Ship to:
[Your warehouse address]

async function calculateVendorScorecard(params: {
  vendorId: string;
  periodDays: number;
}): Promise<{
  onTimeRatePct: number;
  fillRatePct: number;
  defectRatePct: number;
  overallScore: number;   // 0–100
}> {
  const since = new Date(Date.now() - params.periodDays * 86400000);

  const pos = await db.purchaseOrders.findAll({
    vendor_id: params.vendorId,
    status: { in: ['received', 'partial'] },
    created_at: { gte: since },
  });

  if (pos.length === 0) return { onTimeRatePct: 0, fillRatePct: 0, defectRatePct: 0, overallScore: 0 };

  // On-time: PO received on or before expected delivery date
  const onTimeCount = pos.filter(po => po.received_at && po.received_at <= new Date(`${po.expected_delivery}T23:59:59Z`)).length;

  // Fill rate: total received / total ordered
  const allLines = await db.poLines.findByPoIds(pos.map(p => p.id));
  const totalOrdered = allLines.reduce((s, l) => s + l.quantity_ordered, 0);
  const totalReceived = allLines.reduce((s, l) => s + l.quantity_received, 0);

  // Defect rate: damaged units / total received
  const totalDamaged = await db.damagedReceipts.sumByVendorAndPeriod(params.vendorId, since);

  const onTimeRatePct = (onTimeCount / pos.length) * 100;
  const fillRatePct = totalOrdered > 0 ? (totalReceived / totalOrdered) * 100 : 0;
  const defectRatePct = totalReceived > 0 ? (totalDamaged / totalReceived) * 100 : 0;

  // Weighted score: on-time 40%, fill rate 40%, defect-free 20%
  const overallScore = Math.round(
    (onTimeRatePct * 0.4) + (fillRatePct * 0.4) + ((100 - defectRatePct) * 0.2)
  );

  return { onTimeRatePct, fillRatePct, defectRatePct, overallScore };
}