validations added to production order
diff --git a/erpnext/manufacturing/doctype/production_order/production_order.py b/erpnext/manufacturing/doctype/production_order/production_order.py
index a962248..67b53f6 100644
--- a/erpnext/manufacturing/doctype/production_order/production_order.py
+++ b/erpnext/manufacturing/doctype/production_order/production_order.py
@@ -35,6 +35,7 @@
 		self.validate_sales_order()
 		self.validate_warehouse()
 		self.calculate_operating_cost()
+		self.validate_delivery_date()
 
 		from erpnext.utilities.transaction_base import validate_uom_is_integer
 		validate_uom_is_integer(self, "stock_uom", ["qty", "produced_qty"])
@@ -219,6 +220,13 @@
 		else:
 			self.actual_start_date = None
 			self.actual_end_date = None
+			
+	def validate_delivery_date(self):
+		if self.planned_start_date and self.expected_delivery_date and getdate(self.expected_delivery_date) < getdate(self.planned_start_date):
+			frappe.throw(_("Expected Delivery Date cannot be greater than Planned Start Date"))
+			
+		if self.planned_end_date and self.expected_delivery_date and getdate(self.expected_delivery_date) < getdate(self.planned_end_date):
+			frappe.msgprint(_("Production might not be able to finish by the Expected Delivery Date."))
 
 @frappe.whitelist()
 def get_item_details(item):