diff --git a/docs/buildscript.md b/docs/buildscript.md
index 2655770..d39eab4 100644
--- a/docs/buildscript.md
+++ b/docs/buildscript.md
@@ -26,7 +26,7 @@ Possible group names:
   - `tutorial` to process`tutorial/{readme.md,tutorial*.*}`
   - `demos` to process`examples/demo*.*`
 
-  Affected filetypes: `.gv`, `.bom.tsv`, `.png`, `.svg`, `.html`
+  Affected filetypes: `.gv`, `.tsv`, `.png`, `.svg`, `.html`
 
 
 ## Usage hints
diff --git a/src/wireviz/wireviz.py b/src/wireviz/wireviz.py
index ec3cde2..5ce37fc 100755
--- a/src/wireviz/wireviz.py
+++ b/src/wireviz/wireviz.py
@@ -30,6 +30,7 @@ def parse(
     output_name: Union[None, str] = None,
     image_paths: Union[Path, str, List] = [],
     extra_metadata: Dict = {},
+    shared_bom: Dict = {},
 ) -> Any:
     """
     This function takes an input, parses it as a WireViz Harness file,
@@ -114,6 +115,7 @@ def parse(
         metadata=Metadata(**yaml_data.get("metadata", {}), **extra_metadata),
         options=Options(**yaml_data.get("options", {})),
         tweak=Tweak(**yaml_data.get("tweak", {})),
+        shared_bom=shared_bom,
     )
     # others
     # store mapping of components to their respective template
diff --git a/src/wireviz/wv_bom.py b/src/wireviz/wv_bom.py
index 165038f..bd0c861 100644
--- a/src/wireviz/wv_bom.py
+++ b/src/wireviz/wv_bom.py
@@ -15,7 +15,6 @@ MAX_DESCRIPTION = 40
 
 BomEntry = namedtuple("BomEntry", "category qty designators")
 BomHash = namedtuple("BomHash", BOM_HASH_FIELDS)
-BomHashList = namedtuple("BomHashList", BOM_HASH_FIELDS)
 PartNumberInfo = namedtuple("PartNumberInfo", "pn manufacturer mpn supplier spn")
 
 # TODO: different BOM modes
diff --git a/src/wireviz/wv_cli.py b/src/wireviz/wv_cli.py
index bdba966..c944242 100644
--- a/src/wireviz/wv_cli.py
+++ b/src/wireviz/wv_cli.py
@@ -21,6 +21,7 @@ format_codes = {
     "P": "pdf",
     "s": "svg",
     "t": "tsv",
+    "b": "shared_bom",
 }
 
 
@@ -119,6 +120,8 @@ def cli(file, format, prepend, output_dir, output_name, version):
     else:
         prepend_input = ""
 
+    harness = None
+    shared_bom = {}
     sheet_current = 1
     # run WireVIz on each input file
     for file in filepaths:
@@ -151,14 +154,20 @@ def cli(file, format, prepend, output_dir, output_name, version):
         for p in prepend:
             image_paths.add(Path(p).parent)
 
-        wv.parse(
+        harness = wv.parse(
             yaml_input,
-            output_formats=output_formats,
+            return_types=("harness"),
+            output_formats=[f for f in output_formats if f != "shared_bom"],
             output_dir=_output_dir,
             output_name=_output_name,
             image_paths=list(image_paths),
             extra_metadata=extra_metadata,
+            shared_bom=shared_bom,
         )
+    if "shared_bom" in output_formats:
+        _output_dir = file.parent if not output_dir else output_dir
+        harness.output(str(Path(_output_dir) / "shared_bom"), fmt="shared_bom")
+        shared_bom = harness.shared_bom
 
     print()  # blank line after execution
 
diff --git a/src/wireviz/wv_harness.py b/src/wireviz/wv_harness.py
index ec5fb59..e5bc5fe 100644
--- a/src/wireviz/wv_harness.py
+++ b/src/wireviz/wv_harness.py
@@ -3,7 +3,7 @@
 from collections import defaultdict
 from dataclasses import dataclass, field
 from pathlib import Path
-from typing import List
+from typing import Dict, List
 
 from graphviz import Graph
 
@@ -45,6 +45,7 @@ class Harness:
     options: Options
     tweak: Tweak
     additional_bom_items: List[AdditionalComponent] = field(default_factory=list)
+    shared_bom: Dict = field(default_factory=dict)
 
     def __post_init__(self):
         self.connectors = {}
@@ -119,9 +120,21 @@ class Harness:
                 ),  # x[0] = key, x[1] = value
             )
         )
-        # assign BOM IDs
-        for id, key in enumerate(self.bom.keys(), 1):
-            self.bom[key]["id"] = id
+
+        next_id = len(self.shared_bom) + 1
+        # TODO: for each harness, track a (harness_name, qty) pair
+        for key, values in self.bom.items():
+            if key in self.shared_bom:
+                self.shared_bom[key]["qty"] += values["qty"]
+                values["id"] = self.shared_bom[key]["id"]
+                continue
+            self.shared_bom[key] = values
+            self.shared_bom[key]["id"] = next_id
+            values["id"] = next_id
+            next_id += 1
+
+        # print(f'bom length: {len(self.bom)}, shared_bom length: {len(self.shared_bom)}') # for debugging
+
         # set BOM IDs within components (for BOM bubbles)
         for item in all_bom_relevant_items:
             if item.ignore_in_bom:
@@ -131,6 +144,12 @@ class Harness:
                 continue
             item.bom_id = self.bom[item.bom_hash]["id"]
 
+        self.bom = dict(
+            sorted(
+                self.bom.items(),
+                key=lambda x: (x[1]["id"],),
+            )
+        )
         # print_bom_table(self.bom)  # for debugging
 
     def _add_to_internal_bom(self, item: Component):
@@ -412,6 +431,11 @@ class Harness:
         if "csv" in fmt:
             # TODO: implement CSV output (preferrably using CSV library)
             print("CSV output is not yet supported")
+        if "shared_bom" in fmt:
+            shared_bomlist = bom_list(self.shared_bom)
+            shared_bom_tsv = bom2tsv(shared_bomlist)
+            open_file_write(f"{filename}.tsv").write(shared_bom_tsv)
+
         # HTML output
         if "html" in fmt:
             generate_html_output(filename, bomlist, self.metadata, self.options)