diff --git a/erpnext/manufacturing/doctype/work_order/work_order.py b/erpnext/manufacturing/doctype/work_order/work_order.py
index 9b6f95f25df..268918eca00 100644
--- a/erpnext/manufacturing/doctype/work_order/work_order.py
+++ b/erpnext/manufacturing/doctype/work_order/work_order.py
@@ -2433,24 +2433,27 @@ def make_stock_entry(
 
 @frappe.whitelist()
 <<<<<<< HEAD
+<<<<<<< HEAD
 def get_default_warehouse(company):
 =======
 def get_disassembly_available_qty(stock_entry_name: str) -> float:
+=======
+def get_disassembly_available_qty(stock_entry_name: str, current_se_name: str | None = None) -> float:
+>>>>>>> 6394dead72 (fix: validate qty that can be disassembled from source stock entry.)
 	se = frappe.db.get_value("Stock Entry", stock_entry_name, ["fg_completed_qty"], as_dict=True)
 	if not se:
 		return 0.0
 
-	already_disassembled = flt(
-		frappe.db.get_value(
-			"Stock Entry",
-			{
-				"source_stock_entry": stock_entry_name,
-				"purpose": "Disassemble",
-				"docstatus": 1,
-			},
-			[{"SUM": "fg_completed_qty"}],
-		)
-	)
+	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"}]))
 
 	return flt(se.fg_completed_qty) - already_disassembled
 
diff --git a/erpnext/stock/doctype/stock_entry/stock_entry.py b/erpnext/stock/doctype/stock_entry/stock_entry.py
index 8d5c1fe60dc..c1eeec3eaf4 100644
--- a/erpnext/stock/doctype/stock_entry/stock_entry.py
+++ b/erpnext/stock/doctype/stock_entry/stock_entry.py
@@ -247,6 +247,7 @@ class StockEntry(StockController, SubcontractingInwardController):
 		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()
@@ -847,6 +848,26 @@ class StockEntry(StockController, SubcontractingInwardController):
 		elif self.purpose != "Material Transfer":
 			self.work_order = None
 
+	def validate_source_stock_entry(self):
+		if not self.get("source_stock_entry"):
+			return
+
+		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)