diff --git a/src/database/schemas/inventory/shipment.schema.js b/src/database/schemas/inventory/shipment.schema.js
index 67331ae..16bf11d 100644
--- a/src/database/schemas/inventory/shipment.schema.js
+++ b/src/database/schemas/inventory/shipment.schema.js
@@ -1,43 +1,108 @@
 import mongoose from 'mongoose';
 import { generateId } from '../../utils.js';
 const { Schema } = mongoose;
-
-const shipmentItemSchema = new Schema({
-  itemType: { type: String, required: true },
-  item: { type: Schema.Types.ObjectId, refPath: 'itemType', required: true },
-  quantity: { type: Number, required: true },
-  itemCost: { type: Number, required: true },
-  totalCost: { type: Number, required: true },
-  totalCostWithTax: { type: Number, required: true },
-  taxRate: { type: Schema.Types.ObjectId, ref: 'taxRate', required: false },
-});
+import { purchaseOrderModel } from './purchaseorder.schema.js';
+import { taxRateModel } from '../management/taxrate.schema.js';
+import { aggregateRollups, editObject, getObject } from '../../database.js';
 
 const shipmentSchema = new Schema(
   {
     _reference: { type: String, default: () => generateId()() },
-    purchaseOrder: { type: Schema.Types.ObjectId, ref: 'purchaseOrder', required: true },
-    vendor: { type: Schema.Types.ObjectId, ref: 'vendor', required: true },
+    orderType: { type: String, required: true },
+    order: { type: Schema.Types.ObjectId, refPath: 'orderType', required: true },
     courierService: { type: Schema.Types.ObjectId, ref: 'courierService', required: false },
     trackingNumber: { type: String, required: false },
-    items: [shipmentItemSchema],
-    cost: { net: { type: Number, required: true }, gross: { type: Number, required: true } },
-    shippedDate: { type: Date, required: false },
-    expectedDeliveryDate: { type: Date, required: false },
-    actualDeliveryDate: { type: Date, required: false },
+    amount: { type: Number, required: true },
+    amountWithTax: { type: Number, required: true },
+    taxRate: { type: Schema.Types.ObjectId, ref: 'taxRate', required: false },
+    shippedAt: { type: Date, required: false },
+    expectedAt: { type: Date, required: false },
+    deliveredAt: { type: Date, required: false },
+    cancelledAt: { type: Date, required: false },
     state: {
       type: {
         type: String,
         required: true,
-        default: 'pending',
-        enum: ['pending', 'shipped', 'in_transit', 'delivered', 'cancelled'],
       },
     },
-    notes: { type: String },
-    timestamp: { type: Date, default: Date.now },
   },
   { timestamps: true }
 );
 
+shipmentSchema.statics.recalculate = async function (shipment, user) {
+  // Only purchase orders are supported for now
+  if (shipment.orderType !== 'purchaseOrder') {
+    return;
+  }
+
+  const orderId = shipment.order?._id || shipment.order;
+  if (!orderId) {
+    return;
+  }
+
+  var taxRate = shipment.taxRate;
+
+  if (shipment.taxRate?._id && Object.keys(shipment.taxRate).length == 1) {
+    taxRate = await getObject({
+      model: taxRateModel,
+      id: shipment.taxRate._id,
+      cached: true,
+    });
+  }
+
+  const amountWithTax = shipment.amount * (1 + (taxRate?.rate || 0) / 100);
+  await editObject({
+    model: shipmentModel,
+    id: shipment._id,
+    updateData: {
+      amountWithTax: amountWithTax,
+    },
+    user,
+    recalculate: false,
+  });
+
+  const rollupResults = await aggregateRollups({
+    model: this,
+    baseFilter: {
+      order: new mongoose.Types.ObjectId(orderId),
+      orderType: shipment.orderType,
+    },
+    rollupConfigs: [
+      {
+        name: 'shipmentTotals',
+        rollups: [
+          { name: 'amount', property: 'amount', operation: 'sum' },
+          { name: 'amountWithTax', property: 'amountWithTax', operation: 'sum' },
+        ],
+      },
+    ],
+  });
+
+  const totals = rollupResults.shipmentTotals || {};
+  const totalShippingAmount = totals.amount.sum?.toFixed(2) || 0;
+  const totalShippingAmountWithTax = totals.amountWithTax.sum?.toFixed(2) || 0;
+
+  const purchaseOrder = await getObject({
+    model: purchaseOrderModel,
+    id: orderId,
+    cached: true,
+  });
+
+  const grandTotalAmount =
+    parseFloat(purchaseOrder.totalAmountWithTax || 0) + parseFloat(totalShippingAmountWithTax || 0);
+  await editObject({
+    model: purchaseOrderModel,
+    id: orderId,
+    updateData: {
+      shippingAmount: parseFloat(totalShippingAmount).toFixed(2),
+      shippingAmountWithTax: parseFloat(totalShippingAmountWithTax).toFixed(2),
+      grandTotalAmount: parseFloat(grandTotalAmount).toFixed(2),
+    },
+    user,
+    recalculate: false,
+  });
+};
+
 // Add virtual id getter
 shipmentSchema.virtual('id').get(function () {
   return this._id;