diff --git a/erpnext/manufacturing/doctype/work_order/test_work_order.py b/erpnext/manufacturing/doctype/work_order/test_work_order.py
index c23db9aa682..374caf369ea 100644
--- a/erpnext/manufacturing/doctype/work_order/test_work_order.py
+++ b/erpnext/manufacturing/doctype/work_order/test_work_order.py
@@ -4,7 +4,7 @@
 
 import frappe
 from frappe.tests.utils import FrappeTestCase, change_settings, timeout
-from frappe.utils import add_days, add_months, add_to_date, cint, flt, now, today
+from frappe.utils import add_days, add_months, add_to_date, cint, flt, now, nowdate, nowtime, today
 
 from erpnext.manufacturing.doctype.job_card.job_card import JobCardCancelError
 from erpnext.manufacturing.doctype.job_card.job_card import make_stock_entry as make_stock_entry_from_jc
@@ -2395,7 +2395,7 @@ class TestWorkOrder(FrappeTestCase):
 
 		stock_entry.submit()
 
-	def test_disassembly_order_with_qty_behavior(self):
+	def test_disassembly_order_with_qty_from_wo_behavior(self):
 		# Create raw material and FG item
 		raw_item = make_item("Test Raw for Disassembly", {"is_stock_item": 1}).name
 		fg_item = make_item("Test FG for Disassembly", {"is_stock_item": 1}).name
@@ -2435,27 +2435,9 @@ class TestWorkOrder(FrappeTestCase):
 		se_for_manufacture = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", wo.qty))
 		se_for_manufacture.submit()
 
-		# Simulate a disassembly stock entry
+		# Disassembly via WO required_items path (no source_stock_entry)
 		disassemble_qty = 4
 		stock_entry = frappe.get_doc(make_stock_entry(wo.name, "Disassemble", disassemble_qty))
-		stock_entry.append(
-			"items",
-			{
-				"item_code": fg_item,
-				"qty": disassemble_qty,
-				"s_warehouse": wo.fg_warehouse,
-			},
-		)
-
-		for bom_item in bom.items:
-			stock_entry.append(
-				"items",
-				{
-					"item_code": bom_item.item_code,
-					"qty": (bom_item.qty / bom.quantity) * disassemble_qty,
-					"t_warehouse": wo.source_warehouse,
-				},
-			)
 
 		wo.reload()
 		stock_entry.save()
@@ -2470,7 +2452,7 @@ class TestWorkOrder(FrappeTestCase):
 			f"Expected FG qty {disassemble_qty}, found {finished_good_entry.qty}",
 		)
 
-		# Assert raw materials
+		# Assert raw materials - qty scaled from WO required_items
 		for item in stock_entry.items:
 			if item.item_code == fg_item:
 				continue
@@ -2494,10 +2476,35 @@ class TestWorkOrder(FrappeTestCase):
 			f"Work Order disassembled_qty mismatch: expected {disassemble_qty}, got {wo.disassembled_qty}",
 		)
 
+		# Second disassembly: explicitly linked to manufacture SE — verifies SE-linked path
+		# (first disassembly auto-set source_stock_entry since there's only one manufacture entry)
+		disassemble_qty_2 = 2
+		stock_entry_2 = frappe.get_doc(
+			make_stock_entry(
+				wo.name, "Disassemble", disassemble_qty_2, source_stock_entry=se_for_manufacture.name
+			)
+		)
+		stock_entry_2.save()
+		stock_entry_2.submit()
+
+		# All rows must trace back to se_for_manufacture
+		for item in stock_entry_2.items:
+			self.assertEqual(item.against_stock_entry, se_for_manufacture.name)
+			self.assertTrue(item.ste_detail)
+
+		# RM qty scaled from the manufacture SE rows
+		rm_row = next((i for i in stock_entry_2.items if i.item_code == raw_item), None)
+		expected_rm_qty = (bom.items[0].qty / bom.quantity) * disassemble_qty_2
+		self.assertAlmostEqual(rm_row.qty, expected_rm_qty, places=3)
+
+		wo.reload()
+		self.assertEqual(wo.disassembled_qty, disassemble_qty + disassemble_qty_2)
+
 	def test_disassembly_with_multiple_manufacture_entries(self):
 		"""
 		Test that disassembly does not create duplicate items when manufacturing
-		is done in multiple batches (multiple manufacture stock entries).
+		is done in multiple batches (multiple manufacture stock entries), including
+		secondary/scrap items.
 
 		Scenario:
 		1. Create Work Order for 10 units
@@ -2506,11 +2513,17 @@ class TestWorkOrder(FrappeTestCase):
 		4. Create Disassembly for 4 units
 		5. Verify no duplicate items in the disassembly stock entry
 		"""
-		# Create RM and FG item
+		# Create RM, scrap and FG item
 		raw_item1 = make_item("Test Raw for Multi Batch Disassembly 1", {"is_stock_item": 1}).name
 		raw_item2 = make_item("Test Raw for Multi Batch Disassembly 2", {"is_stock_item": 1}).name
+		scrap_item = make_item("Test Scrap for Multi Batch Disassembly", {"is_stock_item": 1}).name
 		fg_item = make_item("Test FG for Multi Batch Disassembly", {"is_stock_item": 1}).name
-		bom = make_bom(item=fg_item, quantity=1, raw_materials=[raw_item1, raw_item2], rm_qty=2)
+		bom = make_bom(
+			item=fg_item, quantity=1, raw_materials=[raw_item1, raw_item2], rm_qty=2, do_not_submit=True
+		)
+		# add scrap item
+		bom.append("scrap_items", {"item_code": scrap_item, "stock_qty": 10})
+		bom.submit()
 
 		# Create WO
 		wo = make_wo_order_test_record(production_item=fg_item, qty=10, bom_no=bom.name, status="Not Started")
@@ -2585,7 +2598,7 @@ class TestWorkOrder(FrappeTestCase):
 			f"Found duplicate items in disassembly stock entry: {duplicates}",
 		)
 
-		expected_items = 3  # FG item + 2 raw materials
+		expected_items = 4  # FG item + 2 raw materials + 1 scrap item
 		self.assertEqual(
 			len(stock_entry.items),
 			expected_items,
@@ -2596,6 +2609,16 @@ class TestWorkOrder(FrappeTestCase):
 		fg_item_row = next((i for i in stock_entry.items if i.item_code == fg_item), None)
 		self.assertEqual(fg_item_row.qty, disassemble_qty)
 
+		# Scrap item: should be taken from scrap warehouse in disassembly
+		scrap_row = next((i for i in stock_entry.items if i.item_code == scrap_item), None)
+		self.assertIsNotNone(scrap_row)
+		self.assertEqual(scrap_row.is_scrap_item, 1)
+		self.assertTrue(scrap_row.s_warehouse)
+		self.assertFalse(scrap_row.t_warehouse)
+		self.assertEqual(scrap_row.s_warehouse, wo.scrap_warehouse)
+		# BOM has scrap_qty=10/FG, total produced = 10*10 = 100, disassemble 4/10 → 40
+		self.assertEqual(scrap_row.qty, 40)
+
 		# RM quantities
 		for bom_item in bom.items:
 			expected_qty = (bom_item.qty / bom.quantity) * disassemble_qty
@@ -2607,19 +2630,57 @@ class TestWorkOrder(FrappeTestCase):
 				msg=f"Raw material {bom_item.item_code} qty mismatch",
 			)
 
+		# -- BOM-path disassembly (no source_stock_entry, no work_order) --
+
+		make_stock_entry_test_record(
+			item_code=scrap_item,
+			purpose="Material Receipt",
+			target=wo.fg_warehouse,
+			qty=50,
+			basic_rate=10,
+		)
+
+		bom_disassemble_qty = 2
+		bom_se = frappe.get_doc(
+			{
+				"doctype": "Stock Entry",
+				"stock_entry_type": "Disassemble",
+				"purpose": "Disassemble",
+				"from_bom": 1,
+				"bom_no": bom.name,
+				"fg_completed_qty": bom_disassemble_qty,
+				"from_warehouse": wo.fg_warehouse,
+				"to_warehouse": wo.wip_warehouse,
+				"company": wo.company,
+				"posting_date": nowdate(),
+				"posting_time": nowtime(),
+			}
+		)
+		bom_se.get_items()
+		bom_se.save()
+		bom_se.submit()
+
+		bom_scrap_row = next((i for i in bom_se.items if i.item_code == scrap_item), None)
+		self.assertIsNotNone(bom_scrap_row, "Scrap item must appear in BOM-path disassembly")
+		# v15: BOM scrap_qty=10/FG, no process_loss_per field → qty = 10 * 2 = 20
+		self.assertEqual(
+			bom_scrap_row.qty,
+			20,
+			f"BOM-path disassembly scrap qty mismatch; expected 20, got {bom_scrap_row.qty}",
+		)
+
 	def test_disassembly_with_additional_rm_not_in_bom(self):
 		"""
-		Test that disassembly correctly handles additional raw materials that were
-		manually added during manufacturing (not part of the BOM).
+		Test that SE-linked disassembly includes additional raw materials
+		that were manually added during manufacturing (not part of the BOM).
 
 		Scenario:
 		1. Create Work Order for 10 units with 2 raw materials in BOM
 		2. Transfer raw materials for manufacture
 		3. Manufacture in 2 parts (3 units, then 7 units)
 		4. In each manufacture entry, manually add an extra consumable item
-		   (not in BOM) in proportion to the manufactured qty
-		5. Create Disassembly for 4 units
-		6. Verify that the additional RM is included in disassembly with proportional qty
+		5. Disassemble 3 units linked to first manufacture entry
+		6. Verify additional RM is included with correct proportional qty from SE1
 		"""
 		from erpnext.stock.doctype.stock_entry.test_stock_entry import (
 			make_stock_entry as make_stock_entry_test_record,
@@ -2655,9 +2716,8 @@ class TestWorkOrder(FrappeTestCase):
 		se_for_material_transfer.save()
 		se_for_material_transfer.submit()
 
-		# First Manufacture Entry - 3 units
+		# First Manufacture Entry - 3 units with additional RM
 		se_manufacture1 = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", 3))
-		# Additional RM
 		se_manufacture1.append(
 			"items",
 			{
@@ -2670,9 +2730,8 @@ class TestWorkOrder(FrappeTestCase):
 		se_manufacture1.save()
 		se_manufacture1.submit()
 
-		# Second Manufacture Entry - 7 units
+		# Second Manufacture Entry - 7 units with additional RM
 		se_manufacture2 = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", 7))
-		# AAdditional RM
 		se_manufacture2.append(
 			"items",
 			{
@@ -2688,13 +2747,15 @@ class TestWorkOrder(FrappeTestCase):
 		wo.reload()
 		self.assertEqual(wo.produced_qty, 10)
 
-		# Disassembly for 4 units
-		disassemble_qty = 4
-		stock_entry = frappe.get_doc(make_stock_entry(wo.name, "Disassemble", disassemble_qty))
+		# Disassemble 3 units linked to first manufacture entry
+		disassemble_qty = 3
+		stock_entry = frappe.get_doc(
+			make_stock_entry(wo.name, "Disassemble", disassemble_qty, source_stock_entry=se_manufacture1.name)
+		)
 		stock_entry.save()
 		stock_entry.submit()
 
-		# No duplicate
+		# No duplicates
 		item_counts = {}
 		for item in stock_entry.items:
 			item_code = item.item_code
@@ -2707,16 +2768,15 @@ class TestWorkOrder(FrappeTestCase):
 			f"Found duplicate items in disassembly stock entry: {duplicates}",
 		)
 
-		# Additional RM qty
+		# Additional RM should be included — qty proportional to SE1 (3 units -> 3 additional RM)
 		additional_rm_row = next((i for i in stock_entry.items if i.item_code == additional_rm), None)
 		self.assertIsNotNone(
 			additional_rm_row,
 			f"Additional raw material {additional_rm} not found in disassembly",
 		)
 
-		# intentional full reversal as not part of BOM
-		# eg: dies or consumables used during manufacturing
-		expected_additional_rm_qty = 3 + 7
+		# SE1 had 3 additional RM for 3 manufactured units, disassembling all 3
+		expected_additional_rm_qty = 3
 		self.assertAlmostEqual(
 			additional_rm_row.qty,
 			expected_additional_rm_qty,
@@ -2724,7 +2784,7 @@ class TestWorkOrder(FrappeTestCase):
 			msg=f"Additional RM qty mismatch: expected {expected_additional_rm_qty}, got {additional_rm_row.qty}",
 		)
 
-		# RM qty
+		# BOM RM qty — scaled from SE1's rows
 		for bom_item in bom.items:
 			expected_qty = (bom_item.qty / bom.quantity) * disassemble_qty
 			rm_row = next((i for i in stock_entry.items if i.item_code == bom_item.item_code), None)
@@ -2740,6 +2800,7 @@ class TestWorkOrder(FrappeTestCase):
 		fg_item_row = next((i for i in stock_entry.items if i.item_code == fg_item), None)
 		self.assertEqual(fg_item_row.qty, disassemble_qty)
 
+		# FG + 2 BOM RM + 1 additional RM = 4 items
 		expected_items = 4
 		self.assertEqual(
 			len(stock_entry.items),
@@ -2747,6 +2808,282 @@ class TestWorkOrder(FrappeTestCase):
 			f"Expected {expected_items} items, found {len(stock_entry.items)}",
 		)
 
+		# Verify traceability
+		for item in stock_entry.items:
+			self.assertEqual(item.against_stock_entry, se_manufacture1.name)
+			self.assertTrue(item.ste_detail)
+
+	def test_disassembly_auto_sets_source_stock_entry(self):
+		from erpnext.stock.doctype.stock_entry.test_stock_entry import (
+			make_stock_entry as make_stock_entry_test_record,
+		)
+
+		raw_item = make_item("Test Raw Auto Set Disassembly", {"is_stock_item": 1}).name
+		fg_item = make_item("Test FG Auto Set Disassembly", {"is_stock_item": 1}).name
+		bom = make_bom(item=fg_item, quantity=1, raw_materials=[raw_item], rm_qty=2)
+
+		wo = make_wo_order_test_record(production_item=fg_item, qty=5, bom_no=bom.name, status="Not Started")
+
+		make_stock_entry_test_record(
+			item_code=raw_item, purpose="Material Receipt", target=wo.wip_warehouse, qty=50, basic_rate=100
+		)
+
+		se_transfer = frappe.get_doc(make_stock_entry(wo.name, "Material Transfer for Manufacture", wo.qty))
+		for item in se_transfer.items:
+			item.s_warehouse = wo.wip_warehouse
+		se_transfer.save()
+		se_transfer.submit()
+
+		se_manufacture = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", wo.qty))
+		se_manufacture.submit()
+
+		# Disassemble without specifying source_stock_entry
+		stock_entry = frappe.get_doc(make_stock_entry(wo.name, "Disassemble", 3))
+		stock_entry.save()
+
+		# source_stock_entry should be auto-set since only one manufacture entry
+		self.assertEqual(stock_entry.source_stock_entry, se_manufacture.name)
+
+		# All items should have against_stock_entry linked
+		for item in stock_entry.items:
+			self.assertEqual(item.against_stock_entry, se_manufacture.name)
+			self.assertTrue(item.ste_detail)
+
+		stock_entry.submit()
+
+	def test_disassembly_batch_tracked_items(self):
+		from erpnext.stock.doctype.batch.batch import make_batch
+		from erpnext.stock.doctype.stock_entry.test_stock_entry import (
+			make_stock_entry as make_stock_entry_test_record,
+		)
+
+		wip_wh = "_Test Warehouse - _TC"
+
+		rm_item = make_item(
+			"Test Batch RM for Disassembly SB",
+			{
+				"is_stock_item": 1,
+				"has_batch_no": 1,
+				"create_new_batch": 1,
+				"batch_number_series": "TBRD-RM-.###",
+			},
+		).name
+		fg_item = make_item(
+			"Test Batch FG for Disassembly SB",
+			{
+				"is_stock_item": 1,
+				"has_batch_no": 1,
+				"create_new_batch": 1,
+				"batch_number_series": "TBRD-FG-.###",
+			},
+		).name
+
+		bom = make_bom(item=fg_item, quantity=1, raw_materials=[rm_item], rm_qty=2)
+		wo = make_wo_order_test_record(
+			production_item=fg_item,
+			qty=6,
+			bom_no=bom.name,
+			skip_transfer=1,
+			source_warehouse=wip_wh,
+			status="Not Started",
+		)
+
+		# Two separate RM receipts → two distinct batches (batch_1, batch_2)
+		rm_receipt_1 = make_stock_entry_test_record(
+			item_code=rm_item, purpose="Material Receipt", target=wip_wh, qty=6, basic_rate=100
+		)
+		rm_batch_1 = get_batch_from_bundle(
+			frappe.db.get_value(
+				"Stock Entry Detail",
+				{"parent": rm_receipt_1.name, "item_code": rm_item},
+				"serial_and_batch_bundle",
+			)
+		)
+
+		rm_receipt_2 = make_stock_entry_test_record(
+			item_code=rm_item, purpose="Material Receipt", target=wip_wh, qty=6, basic_rate=100
+		)
+		rm_batch_2 = get_batch_from_bundle(
+			frappe.db.get_value(
+				"Stock Entry Detail",
+				{"parent": rm_receipt_2.name, "item_code": rm_item},
+				"serial_and_batch_bundle",
+			)
+		)
+
+		self.assertNotEqual(rm_batch_1, rm_batch_2, "Two receipts must create two distinct RM batches")
+
+		fg_batch_1 = make_batch(frappe._dict(item=fg_item))
+		fg_batch_2 = make_batch(frappe._dict(item=fg_item))
+
+		# Manufacture entry 1 — 3 FG using batch_1 RM/FG
+		se_manufacture_1 = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", 3))
+		for row in se_manufacture_1.items:
+			if row.item_code == rm_item:
+				row.batch_no = rm_batch_1
+				row.use_serial_batch_fields = 1
+			elif row.item_code == fg_item:
+				row.batch_no = fg_batch_1
+				row.use_serial_batch_fields = 1
+		se_manufacture_1.save()
+		se_manufacture_1.submit()
+
+		# Manufacture entry 2 — 3 FG using batch_2 RM/FG
+		se_manufacture_2 = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", 3))
+		for row in se_manufacture_2.items:
+			if row.item_code == rm_item:
+				row.batch_no = rm_batch_2
+				row.use_serial_batch_fields = 1
+			elif row.item_code == fg_item:
+				row.batch_no = fg_batch_2
+				row.use_serial_batch_fields = 1
+		se_manufacture_2.save()
+		se_manufacture_2.submit()
+
+		# Disassemble 2 units from SE_1 only — must use SE_1's batches, not SE_2's
+		disassemble_qty = 2
+		stock_entry = frappe.get_doc(
+			make_stock_entry(
+				wo.name, "Disassemble", disassemble_qty, source_stock_entry=se_manufacture_1.name
+			)
+		)
+		stock_entry.save()
+		stock_entry.submit()
+
+		# FG row: must use fg_batch_1 exclusively (fg_batch_2 must not appear)
+		fg_row = next((i for i in stock_entry.items if i.item_code == fg_item), None)
+		self.assertIsNotNone(fg_row)
+		self.assertTrue(fg_row.serial_and_batch_bundle, "FG row must have a serial_and_batch_bundle")
+		self.assertEqual(get_batch_from_bundle(fg_row.serial_and_batch_bundle), fg_batch_1)
+		self.assertNotEqual(get_batch_from_bundle(fg_row.serial_and_batch_bundle), fg_batch_2)
+
+		# RM row: must use rm_batch_1 exclusively (rm_batch_2 must not appear)
+		rm_row = next((i for i in stock_entry.items if i.item_code == rm_item), None)
+		self.assertIsNotNone(rm_row)
+		self.assertTrue(rm_row.serial_and_batch_bundle, "RM row must have a serial_and_batch_bundle")
+		self.assertEqual(get_batch_from_bundle(rm_row.serial_and_batch_bundle), rm_batch_1)
+		self.assertNotEqual(get_batch_from_bundle(rm_row.serial_and_batch_bundle), rm_batch_2)
+
+		# RM qty: 2 FG disassembled x 2 RM per FG = 4
+		self.assertAlmostEqual(rm_row.qty, 4.0, places=3)
+
+	def test_disassembly_serial_tracked_items(self):
+		from frappe.model.naming import make_autoname
+
+		from erpnext.stock.doctype.stock_entry.test_stock_entry import (
+			make_stock_entry as make_stock_entry_test_record,
+		)
+
+		wip_wh = "_Test Warehouse - _TC"
+
+		rm_item = make_item(
+			"Test Serial RM for Disassembly SB",
+			{"is_stock_item": 1, "has_serial_no": 1, "serial_no_series": "TSRD-RM-.####"},
+		).name
+		fg_item = make_item(
+			"Test Serial FG for Disassembly SB",
+			{"is_stock_item": 1, "has_serial_no": 1, "serial_no_series": "TSRD-FG-.####"},
+		).name
+
+		bom = make_bom(item=fg_item, quantity=1, raw_materials=[rm_item], rm_qty=2)
+		wo = make_wo_order_test_record(
+			production_item=fg_item,
+			qty=6,
+			bom_no=bom.name,
+			skip_transfer=1,
+			source_warehouse=wip_wh,
+			status="Not Started",
+		)
+
+		# Two separate RM receipts → two disjoint sets of serial numbers
+		rm_receipt_1 = make_stock_entry_test_record(
+			item_code=rm_item, purpose="Material Receipt", target=wip_wh, qty=6, basic_rate=100
+		)
+		rm_serials_1 = get_serial_nos_from_bundle(
+			frappe.db.get_value(
+				"Stock Entry Detail",
+				{"parent": rm_receipt_1.name, "item_code": rm_item},
+				"serial_and_batch_bundle",
+			)
+		)
+		self.assertEqual(len(rm_serials_1), 6)
+
+		rm_receipt_2 = make_stock_entry_test_record(
+			item_code=rm_item, purpose="Material Receipt", target=wip_wh, qty=6, basic_rate=100
+		)
+		rm_serials_2 = get_serial_nos_from_bundle(
+			frappe.db.get_value(
+				"Stock Entry Detail",
+				{"parent": rm_receipt_2.name, "item_code": rm_item},
+				"serial_and_batch_bundle",
+			)
+		)
+		self.assertEqual(len(rm_serials_2), 6)
+		self.assertFalse(
+			set(rm_serials_1) & set(rm_serials_2), "Two receipts must produce disjoint RM serial sets"
+		)
+
+		# Pre-generate two sets of FG serial numbers
+		series = frappe.db.get_value("Item", fg_item, "serial_no_series")
+		fg_serials_1 = [make_autoname(series) for _ in range(3)]
+		fg_serials_2 = [make_autoname(series) for _ in range(3)]
+
+		# Manufacture entry 1 — consumes rm_serials_1, produces fg_serials_1
+		se_manufacture_1 = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", 3))
+		for row in se_manufacture_1.items:
+			if row.item_code == rm_item:
+				row.serial_no = "\n".join(rm_serials_1)
+				row.use_serial_batch_fields = 1
+			elif row.item_code == fg_item:
+				row.serial_no = "\n".join(fg_serials_1)
+				row.use_serial_batch_fields = 1
+		se_manufacture_1.save()
+		se_manufacture_1.submit()
+
+		# Manufacture entry 2 — consumes rm_serials_2, produces fg_serials_2
+		se_manufacture_2 = frappe.get_doc(make_stock_entry(wo.name, "Manufacture", 3))
+		for row in se_manufacture_2.items:
+			if row.item_code == rm_item:
+				row.serial_no = "\n".join(rm_serials_2)
+				row.use_serial_batch_fields = 1
+			elif row.item_code == fg_item:
+				row.serial_no = "\n".join(fg_serials_2)
+				row.use_serial_batch_fields = 1
+		se_manufacture_2.save()
+		se_manufacture_2.submit()
+
+		# Disassemble 2 units from SE_1 only — must use SE_1's serials, not SE_2's
+		disassemble_qty = 2
+		stock_entry = frappe.get_doc(
+			make_stock_entry(
+				wo.name, "Disassemble", disassemble_qty, source_stock_entry=se_manufacture_1.name
+			)
+		)
+		stock_entry.save()
+		stock_entry.submit()
+
+		# FG row: 2 serials consumed — must be subset of fg_serials_1, disjoint from fg_serials_2
+		fg_row = next((i for i in stock_entry.items if i.item_code == fg_item), None)
+		self.assertIsNotNone(fg_row)
+		self.assertTrue(fg_row.serial_and_batch_bundle, "FG row must have a serial_and_batch_bundle")
+		fg_dasm_serials = get_serial_nos_from_bundle(fg_row.serial_and_batch_bundle)
+		self.assertEqual(len(fg_dasm_serials), disassemble_qty)
+		self.assertTrue(set(fg_dasm_serials).issubset(set(fg_serials_1)))
+		self.assertFalse(
+			set(fg_dasm_serials) & set(fg_serials_2), "Disassembly must not use SE_2's FG serials"
+		)
+
+		# RM row: 4 serials returned (2 FG x 2 RM each) — subset of rm_serials_1, disjoint from rm_serials_2
+		rm_row = next((i for i in stock_entry.items if i.item_code == rm_item), None)
+		self.assertIsNotNone(rm_row)
+		self.assertTrue(rm_row.serial_and_batch_bundle, "RM row must have a serial_and_batch_bundle")
+		rm_dasm_serials = get_serial_nos_from_bundle(rm_row.serial_and_batch_bundle)
+		self.assertEqual(len(rm_dasm_serials), disassemble_qty * 2)
+		self.assertTrue(set(rm_dasm_serials).issubset(set(rm_serials_1)))
+		self.assertFalse(
+			set(rm_dasm_serials) & set(rm_serials_2), "Disassembly must not use SE_2's RM serials"
+		)
+
 	def test_components_alternate_item_for_bom_based_manufacture_entry(self):
 		frappe.db.set_single_value("Manufacturing Settings", "backflush_raw_materials_based_on", "BOM")
 		frappe.db.set_single_value("Manufacturing Settings", "validate_components_quantities_per_bom", 1)
diff --git a/erpnext/manufacturing/doctype/work_order/work_order.js b/erpnext/manufacturing/doctype/work_order/work_order.js
index f8bbab0ff95..6e20e789899 100644
--- a/erpnext/manufacturing/doctype/work_order/work_order.js
+++ b/erpnext/manufacturing/doctype/work_order/work_order.js
@@ -415,7 +415,7 @@ frappe.ui.form.on("Work Order", {
 
 	make_disassembly_order(frm) {
 		erpnext.work_order
-			.show_prompt_for_qty_input(frm, "Disassemble")
+			.show_disassembly_prompt(frm)
 			.then((data) => {
 				if (flt(data.qty) <= 0) {
 					frappe.msgprint(__("Disassemble Qty cannot be less than or equal to <b>0</b>."));
@@ -425,11 +425,14 @@ frappe.ui.form.on("Work Order", {
 					work_order_id: frm.doc.name,
 					purpose: "Disassemble",
 					qty: data.qty,
+					source_stock_entry: data.source_stock_entry,
 				});
 			})
 			.then((stock_entry) => {
-				frappe.model.sync(stock_entry);
-				frappe.set_route("Form", stock_entry.doctype, stock_entry.name);
+				if (stock_entry) {
+					frappe.model.sync(stock_entry);
+					frappe.set_route("Form", stock_entry.doctype, stock_entry.name);
+				}
 			});
 	},
 
@@ -879,6 +882,60 @@ erpnext.work_order = {
 		return flt(max, precision("qty"));
 	},
 
+	show_disassembly_prompt: function (frm) {
+		let max_qty = flt(frm.doc.produced_qty - frm.doc.disassembled_qty);
+
+		let fields = [
+			{
+				fieldtype: "Link",
+				label: __("Source Manufacture Entry"),
+				fieldname: "source_stock_entry",
+				options: "Stock Entry",
+				description: __("Optional. Select a specific manufacture entry to reverse."),
+				get_query: () => {
+					return {
+						filters: {
+							work_order: frm.doc.name,
+							purpose: "Manufacture",
+							docstatus: 1,
+						},
+					};
+				},
+				onchange: async function () {
+					if (!frm.disassembly_prompt) return;
+
+					let se_name = this.value;
+					let qty = max_qty;
+					if (se_name) {
+						qty = await frappe.xcall(
+							"erpnext.manufacturing.doctype.work_order.work_order.get_disassembly_available_qty",
+							{ stock_entry_name: se_name }
+						);
+					}
+
+					frm.disassembly_prompt.set_value("qty", qty);
+					frm.disassembly_prompt.fields_dict.qty.set_description(__("Max: {0}", [qty]));
+				},
+			},
+			{
+				fieldtype: "Float",
+				label: __("Qty for {0}", [__("Disassemble")]),
+				fieldname: "qty",
+				description: __("Max: {0}", [max_qty]),
+				default: max_qty,
+			},
+		];
+
+		return new Promise((resolve, reject) => {
+			frm.disassembly_prompt = frappe.prompt(
+				fields,
+				(data) => resolve(data),
+				__("Disassemble"),
+				__("Create")
+			);
+		});
+	},
+
 	show_prompt_for_qty_input: function (frm, purpose) {
 		let max = this.get_max_transferable_qty(frm, purpose);
 
diff --git a/erpnext/manufacturing/doctype/work_order/work_order.py b/erpnext/manufacturing/doctype/work_order/work_order.py
index e1a561958ed..8bc2e7c1953 100644
--- a/erpnext/manufacturing/doctype/work_order/work_order.py
+++ b/erpnext/manufacturing/doctype/work_order/work_order.py
@@ -1485,7 +1485,13 @@ def set_work_order_ops(name):
 
 
 @frappe.whitelist()
-def make_stock_entry(work_order_id, purpose, qty=None, target_warehouse=None):
+def make_stock_entry(
+	work_order_id: str,
+	purpose: str,
+	qty: float | None = None,
+	target_warehouse: str | None = None,
+	source_stock_entry: str | None = None,
+):
 	work_order = frappe.get_doc("Work Order", work_order_id)
 	if not frappe.db.get_value("Warehouse", work_order.wip_warehouse, "is_group"):
 		wip_warehouse = work_order.wip_warehouse
@@ -1522,6 +1528,8 @@ def make_stock_entry(work_order_id, purpose, qty=None, target_warehouse=None):
 	if purpose == "Disassemble":
 		stock_entry.from_warehouse = work_order.fg_warehouse
 		stock_entry.to_warehouse = target_warehouse or work_order.source_warehouse
+		if source_stock_entry:
+			stock_entry.source_stock_entry = source_stock_entry
 
 	stock_entry.set_stock_entry_type()
 	stock_entry.get_items()
@@ -1532,6 +1540,28 @@ def make_stock_entry(work_order_id, purpose, qty=None, target_warehouse=None):
 	return stock_entry.as_dict()
 
 
+@frappe.whitelist()
+def get_disassembly_available_qty(stock_entry_name: str, current_se_name: str | None = None) -> float:
+	se = frappe.db.get_value("Stock Entry", stock_entry_name, ["fg_completed_qty"], as_dict=True)
+	if not se:
+		return 0.0
+
+	filters = {
+		"source_stock_entry": stock_entry_name,
+		"purpose": "Disassemble",
+		"docstatus": 1,
+	}
+
+	if current_se_name:
+		filters["name"] = ("!=", current_se_name)
+
+	already_disassembled = flt(
+		frappe.db.get_value("Stock Entry", filters, "sum(fg_completed_qty)", order_by=None)
+	)
+
+	return flt(se.fg_completed_qty) - already_disassembled
+
+
 @frappe.whitelist()
 def get_default_warehouse():
 	doc = frappe.get_cached_doc("Manufacturing Settings")
diff --git a/erpnext/stock/doctype/stock_entry/stock_entry.js b/erpnext/stock/doctype/stock_entry/stock_entry.js
index fd2860a6f58..3e17748bb8f 100644
--- a/erpnext/stock/doctype/stock_entry/stock_entry.js
+++ b/erpnext/stock/doctype/stock_entry/stock_entry.js
@@ -36,6 +36,16 @@ frappe.ui.form.on("Stock Entry", {
 			};
 		});
 
+		frm.set_query("source_stock_entry", function () {
+			return {
+				filters: {
+					purpose: "Manufacture",
+					docstatus: 1,
+					work_order: frm.doc.work_order || undefined,
+				},
+			};
+		});
+
 		frm.set_query("source_warehouse_address", function () {
 			return {
 				query: "erpnext.controllers.queries.get_warehouse_address",
@@ -219,6 +229,30 @@ frappe.ui.form.on("Stock Entry", {
 		});
 	},
 
+	source_stock_entry: async function (frm) {
+		if (!frm.doc.source_stock_entry || frm.doc.purpose !== "Disassemble") return;
+
+		if (frm._via_source_stock_entry) {
+			frm.call({
+				doc: frm.doc,
+				method: "get_items",
+				callback: function (r) {
+					if (!r.exc) refresh_field("items");
+				},
+			});
+			frm._via_source_stock_entry = false;
+			return;
+		}
+
+		let available_qty = await frappe.xcall(
+			"erpnext.manufacturing.doctype.work_order.work_order.get_disassembly_available_qty",
+			{ stock_entry_name: frm.doc.source_stock_entry }
+		);
+
+		// triggers get_items() via its onchange
+		await frm.set_value("fg_completed_qty", available_qty);
+	},
+
 	outgoing_stock_entry: function (frm) {
 		frappe.call({
 			doc: frm.doc,
@@ -315,6 +349,59 @@ frappe.ui.form.on("Stock Entry", {
 					__("View")
 				);
 			}
+
+			if (frm.doc.purpose === "Manufacture") {
+				frm.add_custom_button(
+					__("Disassemble"),
+					async function () {
+						let available_qty = await frappe.xcall(
+							"erpnext.manufacturing.doctype.work_order.work_order.get_disassembly_available_qty",
+							{ stock_entry_name: frm.doc.name }
+						);
+						frappe.prompt(
+							{
+								fieldtype: "Float",
+								label: __("Qty to Disassemble"),
+								fieldname: "qty",
+								default: available_qty,
+								description: __("Max: {0}", [available_qty]),
+							},
+							async (data) => {
+								if (frm.doc.work_order) {
+									let stock_entry = await frappe.xcall(
+										"erpnext.manufacturing.doctype.work_order.work_order.make_stock_entry",
+										{
+											work_order_id: frm.doc.work_order,
+											purpose: "Disassemble",
+											qty: data.qty,
+											source_stock_entry: frm.doc.name,
+										}
+									);
+									if (stock_entry) {
+										frappe.model.sync(stock_entry);
+										frappe.set_route("Form", stock_entry.doctype, stock_entry.name);
+									}
+								} else {
+									let se = frappe.model.get_new_doc("Stock Entry");
+									se.company = frm.doc.company;
+									se.stock_entry_type = "Disassemble";
+									se.purpose = "Disassemble";
+									se.source_stock_entry = frm.doc.name;
+									se.from_bom = frm.doc.from_bom;
+									se.bom_no = frm.doc.bom_no;
+									se.fg_completed_qty = data.qty;
+									frm._via_source_stock_entry = true;
+
+									frappe.set_route("Form", "Stock Entry", se.name);
+								}
+							},
+							__("Disassemble"),
+							__("Create")
+						);
+					},
+					__("Create")
+				);
+			}
 		}
 
 		if (frm.doc.docstatus === 0) {
@@ -1279,8 +1366,11 @@ erpnext.stock.StockEntry = class StockEntry extends erpnext.stock.StockControlle
 		if (!this.frm.doc.fg_completed_qty || !this.frm.doc.bom_no)
 			frappe.throw(__("BOM and Manufacturing Quantity are required"));
 
-		if (this.frm.doc.work_order || this.frm.doc.bom_no) {
-			// if work order / bom is mentioned, get items
+		if (
+			this.frm.doc.work_order ||
+			this.frm.doc.bom_no ||
+			(this.frm.doc.purpose === "Disassemble" && this.frm.doc.source_stock_entry)
+		) {
 			return this.frm.call({
 				doc: me.frm.doc,
 				freeze: true,
diff --git a/erpnext/stock/doctype/stock_entry/stock_entry.json b/erpnext/stock/doctype/stock_entry/stock_entry.json
index f37a2785252..797bb8ac5dd 100644
--- a/erpnext/stock/doctype/stock_entry/stock_entry.json
+++ b/erpnext/stock/doctype/stock_entry/stock_entry.json
@@ -11,6 +11,7 @@
   "naming_series",
   "stock_entry_type",
   "outgoing_stock_entry",
+  "source_stock_entry",
   "purpose",
   "add_to_transit",
   "work_order",
@@ -120,6 +121,15 @@
    "options": "Stock Entry",
    "read_only": 1
   },
+  {
+   "depends_on": "eval:doc.purpose == 'Disassemble'",
+   "fieldname": "source_stock_entry",
+   "fieldtype": "Link",
+   "label": "Source Stock Entry (Manufacture)",
+   "no_copy": 1,
+   "options": "Stock Entry",
+   "print_hide": 1
+  },
   {
    "bold": 1,
    "fetch_from": "stock_entry_type.purpose",
diff --git a/erpnext/stock/doctype/stock_entry/stock_entry.py b/erpnext/stock/doctype/stock_entry/stock_entry.py
index fec92256108..5f9e55cee50 100644
--- a/erpnext/stock/doctype/stock_entry/stock_entry.py
+++ b/erpnext/stock/doctype/stock_entry/stock_entry.py
@@ -28,7 +28,6 @@ from erpnext.buying.utils import check_on_hold_or_closed_status
 from erpnext.controllers.taxes_and_totals import init_landed_taxes_and_totals
 from erpnext.manufacturing.doctype.bom.bom import (
 	add_additional_cost,
-	get_bom_items_as_dict,
 	get_op_cost_from_sub_assemblies,
 	get_scrap_items_from_sub_assemblies,
 	validate_bom_no,
@@ -143,6 +142,7 @@ class StockEntry(StockController):
 		select_print_heading: DF.Link | None
 		set_posting_time: DF.Check
 		source_address_display: DF.SmallText | None
+		source_stock_entry: DF.Link | None
 		source_warehouse_address: DF.Link | None
 		stock_entry_type: DF.Link
 		subcontracting_order: DF.Link | None
@@ -217,6 +217,7 @@ class StockEntry(StockController):
 		self.validate_warehouse()
 		self.validate_warehouse_of_sabb()
 		self.validate_work_order()
+		self.validate_source_stock_entry()
 		self.validate_bom()
 		self.set_process_loss_qty()
 		self.validate_purchase_order()
@@ -293,6 +294,56 @@ class StockEntry(StockController):
 		if self.purpose != "Disassemble":
 			return
 
+		if self.get("source_stock_entry"):
+			self._set_serial_batch_for_disassembly_from_stock_entry()
+		else:
+			self._set_serial_batch_for_disassembly_from_available_materials()
+
+	def _set_serial_batch_for_disassembly_from_stock_entry(self):
+		from erpnext.stock.doctype.serial_and_batch_bundle.serial_and_batch_bundle import (
+			get_voucher_wise_serial_batch_from_bundle,
+		)
+
+		source_fg_qty = flt(frappe.db.get_value("Stock Entry", self.source_stock_entry, "fg_completed_qty"))
+		scale_factor = flt(self.fg_completed_qty) / source_fg_qty if source_fg_qty else 0
+
+		bundle_data = get_voucher_wise_serial_batch_from_bundle(voucher_no=[self.source_stock_entry])
+		source_rows_by_name = {r.name: r for r in self.get_items_from_manufacture_stock_entry()}
+
+		for row in self.items:
+			if not row.ste_detail:
+				continue
+
+			source_row = source_rows_by_name.get(row.ste_detail)
+			if not source_row:
+				continue
+
+			source_warehouse = source_row.s_warehouse or source_row.t_warehouse
+			key = (source_row.item_code, source_warehouse, self.source_stock_entry)
+			source_bundle = bundle_data.get(key, {})
+
+			batches = defaultdict(float)
+			serial_nos = []
+
+			if source_bundle.get("batch_nos"):
+				qty_remaining = row.transfer_qty
+				for batch_no, batch_qty in source_bundle["batch_nos"].items():
+					if qty_remaining <= 0:
+						break
+					alloc = min(abs(flt(batch_qty)) * scale_factor, qty_remaining)
+					batches[batch_no] = alloc
+					qty_remaining -= alloc
+			elif source_row.batch_no:
+				batches[source_row.batch_no] = row.transfer_qty
+
+			if source_bundle.get("serial_nos"):
+				serial_nos = get_serial_nos(source_bundle["serial_nos"])[: int(row.transfer_qty)]
+			elif source_row.serial_no:
+				serial_nos = get_serial_nos(source_row.serial_no)[: int(row.transfer_qty)]
+
+			self._set_serial_batch_bundle_for_disassembly_row(row, serial_nos, batches)
+
+	def _set_serial_batch_for_disassembly_from_available_materials(self):
 		available_materials = get_available_materials(self.work_order, self)
 		for row in self.items:
 			warehouse = row.s_warehouse or row.t_warehouse
@@ -318,34 +369,38 @@ class StockEntry(StockController):
 			if materials.serial_nos:
 				serial_nos = materials.serial_nos[: int(row.transfer_qty)]
 
-			if not serial_nos and not batches:
-				continue
+			self._set_serial_batch_bundle_for_disassembly_row(row, serial_nos, batches)
 
-			bundle_doc = SerialBatchCreation(
-				{
-					"item_code": row.item_code,
-					"warehouse": warehouse,
-					"posting_date": self.posting_date,
-					"posting_time": self.posting_time,
-					"voucher_type": self.doctype,
-					"voucher_no": self.name,
-					"voucher_detail_no": row.name,
-					"qty": row.transfer_qty,
-					"type_of_transaction": "Inward" if row.t_warehouse else "Outward",
-					"company": self.company,
-					"do_not_submit": True,
-				}
-			).make_serial_and_batch_bundle(serial_nos=serial_nos, batch_nos=batches)
+	def _set_serial_batch_bundle_for_disassembly_row(self, row, serial_nos, batches):
+		if not serial_nos and not batches:
+			return
 
-			row.serial_and_batch_bundle = bundle_doc.name
-			row.use_serial_batch_fields = 0
+		warehouse = row.s_warehouse or row.t_warehouse
+		bundle_doc = SerialBatchCreation(
+			{
+				"item_code": row.item_code,
+				"warehouse": warehouse,
+				"posting_date": self.posting_date,
+				"posting_time": self.posting_time,
+				"voucher_type": self.doctype,
+				"voucher_no": self.name,
+				"voucher_detail_no": row.name,
+				"qty": row.transfer_qty,
+				"type_of_transaction": "Inward" if row.t_warehouse else "Outward",
+				"company": self.company,
+				"do_not_submit": True,
+			}
+		).make_serial_and_batch_bundle(serial_nos=serial_nos, batch_nos=batches)
 
-			row.db_set(
-				{
-					"serial_and_batch_bundle": bundle_doc.name,
-					"use_serial_batch_fields": 0,
-				}
-			)
+		row.serial_and_batch_bundle = bundle_doc.name
+		row.use_serial_batch_fields = 0
+
+		row.db_set(
+			{
+				"serial_and_batch_bundle": bundle_doc.name,
+				"use_serial_batch_fields": 0,
+			}
+		)
 
 	def on_submit(self):
 		self.set_serial_batch_for_disassembly()
@@ -729,7 +784,7 @@ class StockEntry(StockController):
 
 			if self.purpose == "Disassemble":
 				if has_bom:
-					if d.is_finished_item:
+					if d.is_finished_item or d.is_scrap_item:
 						d.t_warehouse = None
 						if not d.s_warehouse:
 							frappe.throw(_("Source warehouse is mandatory for row {0}").format(d.idx))
@@ -766,6 +821,36 @@ class StockEntry(StockController):
 		elif self.purpose != "Material Transfer":
 			self.work_order = None
 
+	def validate_source_stock_entry(self):
+		if not self.get("source_stock_entry"):
+			return
+
+		if self.work_order:
+			source_wo = frappe.db.get_value("Stock Entry", self.source_stock_entry, "work_order")
+			if source_wo and source_wo != self.work_order:
+				frappe.throw(
+					_(
+						"Source Stock Entry {0} belongs to Work Order {1}, not {2}. Please use a manufacture entry from the same Work Order."
+					).format(self.source_stock_entry, source_wo, self.work_order),
+					title=_("Work Order Mismatch"),
+				)
+
+		from erpnext.manufacturing.doctype.work_order.work_order import get_disassembly_available_qty
+
+		available_qty = get_disassembly_available_qty(self.source_stock_entry, self.name)
+
+		if flt(self.fg_completed_qty) > available_qty:
+			frappe.throw(
+				_(
+					"Cannot disassemble {0} qty against Stock Entry {1}. Only {2} qty available to disassemble."
+				).format(
+					self.fg_completed_qty,
+					self.source_stock_entry,
+					available_qty,
+				),
+				title=_("Excess Disassembly"),
+			)
+
 	def check_if_operations_completed(self):
 		"""Check if Time Sheets are completed against before manufacturing to capture operating costs."""
 		prod_order = frappe.get_doc("Work Order", self.work_order)
@@ -1958,44 +2043,114 @@ class StockEntry(StockController):
 				)
 
 	def get_items_for_disassembly(self):
-		"""Get items for Disassembly Order"""
+		"""Get items for Disassembly Order.
+
+		Priority:
+		1. From a specific Manufacture Stock Entry (exact reversal)
+		2. From Work Order Manufacture Stock Entries (averaged reversal)
+		3. From BOM (standalone disassembly)
+		"""
+
+		# Auto-set source_stock_entry if WO has exactly one manufacture entry
+		if not self.get("source_stock_entry") and self.work_order:
+			manufacture_entries = frappe.get_all(
+				"Stock Entry",
+				filters={
+					"work_order": self.work_order,
+					"purpose": "Manufacture",
+					"docstatus": 1,
+				},
+				pluck="name",
+				limit_page_length=2,
+			)
+			if len(manufacture_entries) == 1:
+				self.source_stock_entry = manufacture_entries[0]
+
+		if self.get("source_stock_entry"):
+			return self._add_items_for_disassembly_from_stock_entry()
 
 		if self.work_order:
 			return self._add_items_for_disassembly_from_work_order()
 
 		return self._add_items_for_disassembly_from_bom()
 
-	def _add_items_for_disassembly_from_work_order(self):
-		items = self.get_items_from_manufacture_entry()
+	def _add_items_for_disassembly_from_stock_entry(self):
+		source_fg_qty = frappe.db.get_value("Stock Entry", self.source_stock_entry, "fg_completed_qty")
+		if not source_fg_qty:
+			frappe.throw(
+				_("Source Stock Entry {0} has no finished goods quantity").format(self.source_stock_entry)
+			)
 
-		s_warehouse = frappe.db.get_value("Work Order", self.work_order, "fg_warehouse")
+		disassemble_qty = flt(self.fg_completed_qty)
+		scale_factor = disassemble_qty / flt(source_fg_qty)
 
-		items_dict = get_bom_items_as_dict(
-			self.bom_no,
-			self.company,
-			self.fg_completed_qty,
-			fetch_exploded=self.use_multi_level_bom,
-			fetch_qty_in_stock_uom=False,
+		self._append_disassembly_row_from_source(
+			disassemble_qty=disassemble_qty,
+			scale_factor=scale_factor,
 		)
 
-		for row in items:
-			child_row = self.append("items", {})
-			for field, value in row.items():
-				if value is not None:
-					child_row.set(field, value)
+	def _add_items_for_disassembly_from_work_order(self):
+		wo_produced_qty = frappe.db.get_value("Work Order", self.work_order, "produced_qty")
 
-			# update qty and amount from BOM items
-			bom_items = items_dict.get(row.item_code)
-			if bom_items:
-				child_row.qty = bom_items.get("qty", child_row.qty)
-				child_row.amount = bom_items.get("amount", child_row.amount)
+		wo_produced_qty = flt(wo_produced_qty)
+		if wo_produced_qty <= 0:
+			frappe.throw(_("Work Order {0} has no produced qty").format(self.work_order))
 
-			if row.is_finished_item:
-				child_row.qty = self.fg_completed_qty
+		disassemble_qty = flt(self.fg_completed_qty)
+		if disassemble_qty <= 0:
+			frappe.throw(_("Disassemble Qty cannot be less than or equal to 0."))
 
-			child_row.s_warehouse = (self.from_warehouse or s_warehouse) if row.is_finished_item else ""
-			child_row.t_warehouse = row.s_warehouse
-			child_row.is_finished_item = 0 if row.is_finished_item else 1
+		scale_factor = disassemble_qty / wo_produced_qty
+
+		self._append_disassembly_row_from_source(
+			disassemble_qty=disassemble_qty,
+			scale_factor=scale_factor,
+		)
+
+	def _append_disassembly_row_from_source(self, disassemble_qty, scale_factor):
+		for source_row in self.get_items_from_manufacture_stock_entry():
+			if source_row.is_finished_item:
+				qty = disassemble_qty
+				s_warehouse = self.from_warehouse or source_row.t_warehouse
+				t_warehouse = ""
+			elif source_row.s_warehouse:
+				# RM: was consumed FROM s_warehouse -> return TO s_warehouse
+				qty = flt(source_row.qty * scale_factor)
+				s_warehouse = ""
+				t_warehouse = self.to_warehouse or source_row.s_warehouse
+			else:
+				# Scrap/secondary: was produced TO t_warehouse -> take FROM t_warehouse
+				qty = flt(source_row.qty * scale_factor)
+				s_warehouse = source_row.t_warehouse
+				t_warehouse = ""
+
+			item = {
+				"item_code": source_row.item_code,
+				"item_name": source_row.item_name,
+				"description": source_row.description,
+				"stock_uom": source_row.stock_uom,
+				"uom": source_row.uom,
+				"conversion_factor": source_row.conversion_factor,
+				"basic_rate": source_row.basic_rate,
+				"qty": qty,
+				"s_warehouse": s_warehouse,
+				"t_warehouse": t_warehouse,
+				"is_finished_item": source_row.is_finished_item,
+				"is_scrap_item": source_row.is_scrap_item,
+				"bom_no": source_row.bom_no,
+				# batch and serial bundles built on submit
+				"use_serial_batch_fields": 1 if (source_row.batch_no or source_row.serial_no) else 0,
+			}
+
+			if self.source_stock_entry:
+				item.update(
+					{
+						"against_stock_entry": self.source_stock_entry,
+						"ste_detail": source_row.name,
+					}
+				)
+
+			self.append("items", item)
 
 	def _add_items_for_disassembly_from_bom(self):
 		if not self.bom_no or not self.fg_completed_qty:
@@ -2011,37 +2166,64 @@ class StockEntry(StockController):
 
 		self.add_to_stock_entry_detail(item_dict)
 
+		# Scrap items (reverse: take scrap FROM scrap warehouse instead of producing TO it)
+		scrap_items = self.get_bom_scrap_material(self.fg_completed_qty)
+		if scrap_items:
+			scrap_warehouse = self.from_warehouse
+			if self.work_order:
+				wo_values = frappe.db.get_value(
+					"Work Order", self.work_order, ["scrap_warehouse", "fg_warehouse"], as_dict=True
+				)
+				scrap_warehouse = wo_values.scrap_warehouse or scrap_warehouse or wo_values.fg_warehouse
+
+			for item in scrap_items.values():
+				item["from_warehouse"] = scrap_warehouse
+				item["to_warehouse"] = ""
+				item["is_finished_item"] = 0
+
+			self.add_to_stock_entry_detail(scrap_items, bom_no=self.bom_no)
+
 		# Finished goods
 		self.load_items_from_bom()
 
-	def get_items_from_manufacture_entry(self):
-		return frappe.get_all(
-			"Stock Entry",
-			fields=[
-				"`tabStock Entry Detail`.`item_code`",
-				"`tabStock Entry Detail`.`item_name`",
-				"`tabStock Entry Detail`.`description`",
-				"sum(`tabStock Entry Detail`.qty) as qty",
-				"sum(`tabStock Entry Detail`.transfer_qty) as transfer_qty",
-				"`tabStock Entry Detail`.`stock_uom`",
-				"`tabStock Entry Detail`.`uom`",
-				"`tabStock Entry Detail`.`basic_rate`",
-				"`tabStock Entry Detail`.`conversion_factor`",
-				"`tabStock Entry Detail`.`is_finished_item`",
-				"`tabStock Entry Detail`.`batch_no`",
-				"`tabStock Entry Detail`.`serial_no`",
-				"`tabStock Entry Detail`.`s_warehouse`",
-				"`tabStock Entry Detail`.`t_warehouse`",
-				"`tabStock Entry Detail`.`use_serial_batch_fields`",
-			],
-			filters=[
-				["Stock Entry", "purpose", "=", "Manufacture"],
-				["Stock Entry", "work_order", "=", self.work_order],
-				["Stock Entry", "docstatus", "=", 1],
-				["Stock Entry Detail", "docstatus", "=", 1],
-			],
-			order_by="`tabStock Entry Detail`.`idx` desc, `tabStock Entry Detail`.`is_finished_item` desc",
-			group_by="`tabStock Entry Detail`.`item_code`",
+	def get_items_from_manufacture_stock_entry(self):
+		SE = frappe.qb.DocType("Stock Entry")
+		SED = frappe.qb.DocType("Stock Entry Detail")
+		query = frappe.qb.from_(SED).join(SE).on(SED.parent == SE.name).where(SE.docstatus == 1)
+
+		common_fields = [
+			SED.item_code,
+			SED.item_name,
+			SED.description,
+			SED.stock_uom,
+			SED.uom,
+			SED.basic_rate,
+			SED.conversion_factor,
+			SED.is_finished_item,
+			SED.is_scrap_item,
+			SED.batch_no,
+			SED.serial_no,
+			SED.use_serial_batch_fields,
+			SED.s_warehouse,
+			SED.t_warehouse,
+			SED.bom_no,
+		]
+
+		if self.source_stock_entry:
+			return (
+				query.select(SED.name, SED.qty, SED.transfer_qty, *common_fields)
+				.where(SE.name == self.source_stock_entry)
+				.orderby(SED.idx)
+				.run(as_dict=True)
+			)
+
+		return (
+			query.select(Sum(SED.qty).as_("qty"), Sum(SED.transfer_qty).as_("transfer_qty"), *common_fields)
+			.where(SE.purpose == "Manufacture")
+			.where(SE.work_order == self.work_order)
+			.groupby(SED.item_code)
+			.orderby(SED.idx)
+			.run(as_dict=True)
 		)
 
 	@frappe.whitelist()
@@ -2403,7 +2585,7 @@ class StockEntry(StockController):
 		return item_dict
 
 	def get_scrap_items_from_job_card(self):
-		if not self.pro_doc:
+		if not getattr(self, "pro_doc", None):
 			self.set_work_order_details()
 
 		if not self.pro_doc.operations: