diff --git a/erpnext/selling/report/sales_order_analysis/sales_order_analysis.py b/erpnext/selling/report/sales_order_analysis/sales_order_analysis.py
index 63d339a839..29691230f2 100644
--- a/erpnext/selling/report/sales_order_analysis/sales_order_analysis.py
+++ b/erpnext/selling/report/sales_order_analysis/sales_order_analysis.py
@@ -175,7 +175,9 @@ def prepare_data(data, so_elapsed_time, filters):
 				# update existing entry
 				so_row = sales_order_map[so_name]
 				so_row["required_date"] = max(getdate(so_row["delivery_date"]), getdate(row["delivery_date"]))
-				so_row["delay"] = min(so_row["delay"], row["delay"])
+				so_row["delay"] = (
+					min(so_row["delay"], row["delay"]) if row["delay"] and so_row["delay"] else so_row["delay"]
+				)
 
 				# sum numeric columns
 				fields = [