diff --git a/erpnext/manufacturing/doctype/work_order/work_order.py b/erpnext/manufacturing/doctype/work_order/work_order.py
index e2c221487c0..49765f3a79c 100644
--- a/erpnext/manufacturing/doctype/work_order/work_order.py
+++ b/erpnext/manufacturing/doctype/work_order/work_order.py
@@ -202,7 +202,7 @@ class WorkOrder(Document):
 		self.calculate_operating_cost()
 		self.validate_qty()
 		self.validate_transfer_against()
-		self.validate_operation_time()
+		self.validate_operations()
 		self.status = self.get_status()
 		self.validate_workstation_type()
 		self.reset_use_multi_level_bom()
@@ -1499,8 +1499,11 @@ class WorkOrder(Document):
 				title=_("Missing value"),
 			)
 
-	def validate_operation_time(self):
+	def validate_operations(self):
 		for d in self.operations:
+			if not d.batch_size or d.batch_size <= 0:
+				d.batch_size = 1
+
 			if d.time_in_mins <= 0:
 				frappe.throw(_("Operation Time must be greater than 0 for Operation {0}").format(d.operation))