fix: update depreciation schedule when asset value changes for manual depreciation

erpnext/assets/doctype/asset/asset.py

@@ -142,21 +142,84 @@ class Asset(AccountsController):
 		if self.split_from or not self.calculate_depreciation:
 			return
 
-		schedules = []
-		for row in self.get("finance_books"):
-			self.validate_asset_finance_books(row)
-			if not row.rate_of_depreciation:
-				row.rate_of_depreciation = self.get_depreciation_rate(row, on_validate=True)
+		created_schedules = []
+		for fb_row in self.get("finance_books"):
+			self.validate_asset_finance_books(fb_row)
+			if not fb_row.rate_of_depreciation:
+				fb_row.rate_of_depreciation = self.get_depreciation_rate(fb_row, on_validate=True)
 
-			schedule_doc = get_asset_depr_schedule_doc(self.name, "Draft", row.finance_book)
-			if not schedule_doc:
-				schedule_doc = frappe.new_doc("Asset Depreciation Schedule")
-				schedule_doc.asset = self.name
-				schedule_doc.create_depreciation_schedule(row)
-				schedule_doc.save()
-				schedules.append(schedule_doc.name)
+			existing_schedule = get_asset_depr_schedule_doc(self.name, "Draft", fb_row.finance_book)
 
-		self.show_schedule_creation_message(schedules)
+			if not existing_schedule:
+				new_schedule = frappe.new_doc("Asset Depreciation Schedule")
+				new_schedule.asset = self.name
+				new_schedule.create_depreciation_schedule(fb_row)
+				new_schedule.save()
+				created_schedules.append(new_schedule.name)
+				continue
+
+			self.evaluate_and_recreate_depreciation_schedule(existing_schedule, fb_row)
+			created_schedules.append(existing_schedule.name)
+
+		self.show_schedule_creation_message(created_schedules)
+
+	def evaluate_and_recreate_depreciation_schedule(self, schedule_doc, fb_row):
+		"""Determine if depreciation schedule needs to be regenerated and recreate if necessary"""
+
+		asset_details_changed = self.has_asset_details_changed(schedule_doc)
+		depreciation_settings_changed = self.has_depreciation_settings_changed(schedule_doc, fb_row)
+
+		if self.should_regenerate_depreciation_schedule(
+			schedule_doc, asset_details_changed, depreciation_settings_changed
+		):
+			schedule_doc.create_depreciation_schedule(fb_row)
+			schedule_doc.save()
+
+	def has_asset_details_changed(self, schedule_doc):
+		"""Check if core asset details that affect depreciation have changed"""
+		return (
+			self.net_purchase_amount != schedule_doc.net_purchase_amount
+			or self.opening_accumulated_depreciation != schedule_doc.opening_accumulated_depreciation
+			or self.opening_number_of_booked_depreciations
+			!= schedule_doc.opening_number_of_booked_depreciations
+		)
+
+	def has_depreciation_settings_changed(self, schedule_doc, fb_row):
+		"""Check if depreciation calculation settings have changed"""
+
+		# For non-manual depreciation methods, always check for changes
+		if schedule_doc.depreciation_method != "Manual":
+			return True
+
+		# For manual depreciation, check specific parameters
+		return (
+			fb_row.total_number_of_depreciations != schedule_doc.total_number_of_depreciations
+			or fb_row.frequency_of_depreciation != schedule_doc.frequency_of_depreciation
+			or getdate(fb_row.depreciation_start_date)
+			!= schedule_doc.get("depreciation_schedule")[0].schedule_date
+			or fb_row.expected_value_after_useful_life != schedule_doc.expected_value_after_useful_life
+		)
+
+	def should_regenerate_depreciation_schedule(
+		self, schedule_doc, asset_details_changed, depreciation_settings_changed
+	):
+		"""Check all conditions to determine if schedule regeneration is required"""
+
+		# Schedule doesn't exist yet
+		if not schedule_doc.get("depreciation_schedule"):
+			return True
+
+		previous_version = schedule_doc.get_doc_before_save()
+
+		# Schedule is already submitted and no previous version exists
+		if schedule_doc.docstatus != 0 and not previous_version:
+			return True
+
+		# Either asset details or depreciation settings have changed
+		if asset_details_changed or depreciation_settings_changed:
+			return True
+
+		return False
 
 	def set_depr_rate_and_value_after_depreciation(self):
 		if self.split_from: