Update project.py
diff --git a/erpnext/projects/doctype/project/project.py b/erpnext/projects/doctype/project/project.py
index b5ef4bf..a7446a8 100644
--- a/erpnext/projects/doctype/project/project.py
+++ b/erpnext/projects/doctype/project/project.py
@@ -176,6 +176,13 @@
 			from `tabPurchase Invoice Item` where project = %s and docstatus=1""", self.name)
 
 		self.total_purchase_cost = total_purchase_cost and total_purchase_cost[0][0] or 0
+		
+	def update_sales_costing(self):
+		total_sales_cost = frappe.db.sql("""select sum(base_net_amount)
+			from `tabSales Order Item` where project = %s and docstatus=1""", self.name)
+
+		self.total_sales_cost = total_sales_cost and total_sales_cost[0][0] or 0
+				
 
 	def send_welcome_email(self):
 		url = get_url("/project/?name={0}".format(self.name))