diff --git a/src/wireviz/wv_bom.py b/src/wireviz/wv_bom.py
index 0c769f3..867c5cb 100644
--- a/src/wireviz/wv_bom.py
+++ b/src/wireviz/wv_bom.py
@@ -2,7 +2,7 @@
 
 from collections import namedtuple
 from dataclasses import dataclass
-from enum import Enum
+from enum import Enum, IntEnum
 from typing import List, Optional, Union
 
 import tabulate as tabulate_module
@@ -18,7 +18,7 @@ BomHashList = namedtuple("BomHashList", BOM_HASH_FIELDS)
 PartNumberInfo = namedtuple("PartNumberInfo", "pn manufacturer mpn supplier spn")
 
 
-BomCategory = Enum(
+BomCategory = IntEnum(  # to enforce ordering in BOM
     "BomEntry", "CONNECTOR CABLE WIRE ADDITIONAL_INSIDE ADDITIONAL_OUTSIDE"
 )
 QtyMultiplierConnector = Enum(
@@ -65,14 +65,14 @@ def print_bom_debug(bom):
     # fill rows
     for hash, entry in bom.items():
         cells = [
-            0,
+            entry["id"],
             entry["qty"],
             hash.qty_unit,
             hash.description,
             hash.amount.number if hash.amount else None,
             hash.amount.unit if hash.amount else None,
             ", ".join(sorted(entry["designators"])),
-            entry["category"],
+            f"{entry['category']} ({entry['category'].name})",
         ]
         rows.append(cells)
     # remove empty columns
diff --git a/src/wireviz/wv_dataclasses.py b/src/wireviz/wv_dataclasses.py
index ed1b795..fa1805b 100644
--- a/src/wireviz/wv_dataclasses.py
+++ b/src/wireviz/wv_dataclasses.py
@@ -497,7 +497,7 @@ class WireClass:
         else:
             _hash = BomHash(
                 description=self.description,
-                qty_unit=1,
+                qty_unit=None,
                 amount=self.length,
                 partnumbers=self.partnumbers,
             )
diff --git a/src/wireviz/wv_harness.py b/src/wireviz/wv_harness.py
index 2dd00be..f956188 100644
--- a/src/wireviz/wv_harness.py
+++ b/src/wireviz/wv_harness.py
@@ -8,7 +8,7 @@ from typing import List
 from graphviz import Graph
 
 import wireviz.wv_colors
-from wireviz.wv_bom import BomEntry, print_bom_debug
+from wireviz.wv_bom import BomEntry, print_bom_debug, BomCategory
 from wireviz.wv_dataclasses import (
     AUTOGENERATED_PREFIX,
     AdditionalComponent,
@@ -90,6 +90,18 @@ class Harness:
         for item in self.additional_bom_items:
             self._add_to_internal_bom(item)
 
+        # sort BOM by category first, then alphabetically by description within category
+        self.bom = dict(
+            sorted(
+                self.bom.items(),
+                key=lambda x: (x[1]["category"], x[0].description)
+            )
+        )
+
+        # assign BOM IDs
+        for id, key in enumerate(self.bom.keys(), 1):
+            self.bom[key]["id"] = id
+
         print_bom_debug(self.bom)
 
     def _add_to_internal_bom(self, item: Component):
@@ -118,12 +130,12 @@ class Harness:
 
         if isinstance(item, TopLevelGraphicalComponent):
             if isinstance(item, Connector):
-                cat = "connector"
+                cat = BomCategory.CONNECTOR
             elif isinstance(item, Cable):
                 if item.category == "bundle":
-                    cat = "wire"
+                    cat = BomCategory.WIRE
                 else:
-                    cat = "cable"
+                    cat = BomCategory.CABLE
             else:
                 cat = ""
 
@@ -153,10 +165,10 @@ class Harness:
                     hash=comp.bom_hash,
                     designator=item.designator,
                     qty=comp.bom_qty,
-                    category=f"{cat}_additional",
+                    category=BomCategory.ADDITIONAL_INSIDE,
                 )
         elif isinstance(item, AdditionalComponent):
-            cat = "additional"
+            cat = BomCategory.ADDITIONAL_OUTSIDE
             _add(
                 hash=item.bom_hash,
                 qty=item.bom_qty,