diff --git a/InvenTree/order/migrations/0024_salesorderlineitemstockassociation.py b/InvenTree/order/migrations/0024_salesorderlineitemstockassociation.py
new file mode 100644
index 0000000000..bad3914a74
--- /dev/null
+++ b/InvenTree/order/migrations/0024_salesorderlineitemstockassociation.py
@@ -0,0 +1,23 @@
+# Generated by Django 3.0.5 on 2020-04-21 00:14
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0026_stockitem_uid'),
+        ('order', '0023_auto_20200420_2309'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='SalesOrderLineItemStockAssociation',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('line', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='stock_items', to='order.SalesOrderLineItem')),
+                ('stock_item', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='sales_order', to='stock.StockItem')),
+            ],
+        ),
+    ]
diff --git a/InvenTree/order/models.py b/InvenTree/order/models.py
index 2e5cdc3372..1490b45d98 100644
--- a/InvenTree/order/models.py
+++ b/InvenTree/order/models.py
@@ -291,7 +291,7 @@ class SalesOrderAttachment(InvenTreeAttachment):
     Model for storing file attachments against a SalesOrder object
     """
 
-    def getSubDir(self):
+    def getSubdir(self):
         return os.path.join("so_files", str(self.order.id))
 
     order = models.ForeignKey(SalesOrder, on_delete=models.CASCADE, related_name='attachments')
@@ -372,3 +372,18 @@ class SalesOrderLineItem(OrderLineItem):
 
     part = models.ForeignKey(Part, on_delete=models.SET_NULL, related_name='sales_order_line_items', null=True, help_text=_('Part'), limit_choices_to={'salable': True})
 
+
+class SalesOrderLineItemStockAssociation(models.Model):
+    """
+    Associates StockItem objects with a SalesOrderLineItem.
+    This model is used to match stock items with a sales order,
+    for the purpose of sale / packing / shipping etc.
+
+    Attributes:
+        line: ForeignKey link to a SalesOrderLineItem object -> A single SalesOrderLineItem can have multiple associated StockItem objects
+        stock: OneToOne link to a StockItem object -> A StockItem object can only be mapped to a single SalesOrderLineItem
+    """
+
+    line = models.ForeignKey(SalesOrderLineItem, on_delete=models.CASCADE, related_name='stock_items')
+
+    stock_item = models.OneToOneField(StockItem, on_delete=models.CASCADE, related_name='sales_order')
diff --git a/InvenTree/order/templates/order/sales_order_detail.html b/InvenTree/order/templates/order/sales_order_detail.html
index 9d092a5f45..907effebc7 100644
--- a/InvenTree/order/templates/order/sales_order_detail.html
+++ b/InvenTree/order/templates/order/sales_order_detail.html
@@ -51,10 +51,12 @@ $("#so-lines-table").inventreeTable({
             visible: false,
         },
         {
+            field: 'line',
             title: 'Line',
             formatter: function(value, row, index, field) {
                 return index + 1;
             },
+            width: 50,
         },
         {
             sortable: true,
diff --git a/InvenTree/part/templates/part/tabs.html b/InvenTree/part/templates/part/tabs.html
index 0f894a5942..4f23e345b6 100644
--- a/InvenTree/part/templates/part/tabs.html
+++ b/InvenTree/part/templates/part/tabs.html
@@ -25,7 +25,7 @@
     <li{% ifequal tab 'bom' %} class="active"{% endifequal %}>
         <a href="{% url 'part-bom' part.id %}">{% trans "BOM" %}<span class="badge{% if part.is_bom_valid == False %} badge-alert{% endif %}">{{ part.bom_count }}</span></a></li>
     <li{% ifequal tab 'build' %} class="active"{% endifequal %}>
-        <a href="{% url 'part-build' part.id %}">{% trans "Build" %}<span class='badge'>{{ part.builds|length }}</span></a></li>
+        <a href="{% url 'part-build' part.id %}">{% trans "Build" %}<span class='badge'>{{ part.active_builds|length }}</span></a></li>
     {% endif %}
     {% if part.component or part.used_in_count > 0 %}
     <li{% ifequal tab 'used' %} class="active"{% endifequal %}>