diff --git a/erpnext/manufacturing/report/downtime_analysis/test_downtime_analysis.py b/erpnext/manufacturing/report/downtime_analysis/test_downtime_analysis.py
new file mode 100644
index 00000000000..8c1a8292eab
--- /dev/null
+++ b/erpnext/manufacturing/report/downtime_analysis/test_downtime_analysis.py
@@ -0,0 +1,92 @@
+# Copyright (c) 2026, Frappe Technologies Pvt. Ltd. and Contributors
+# See license.txt
+
+
+import frappe
+from frappe.utils import add_days, get_datetime, today
+
+from erpnext.manufacturing.doctype.workstation.test_workstation import make_workstation
+from erpnext.manufacturing.report.downtime_analysis.downtime_analysis import execute
+from erpnext.setup.doctype.employee.test_employee import make_employee
+from erpnext.tests.utils import ERPNextTestSuite
+
+
+class TestDowntimeAnalysis(ERPNextTestSuite):
+	def setUp(self):
+		self.workstation = make_workstation(workstation="_Test Downtime Workstation").name
+		self.other_workstation = make_workstation(workstation="_Test Downtime Workstation 2").name
+		self.operator = make_employee("test_downtime_operator@example.com", company="_Test Company")
+
+		# from_time / to_time are two hours apart -> downtime of 120 minutes (2 hours).
+		self.from_time = get_datetime(f"{today()} 09:00:00")
+		self.to_time = get_datetime(f"{today()} 11:00:00")
+		self.entry = self.make_downtime_entry(self.workstation)
+
+	def make_downtime_entry(self, workstation, **extra):
+		values = {
+			"doctype": "Downtime Entry",
+			"workstation": workstation,
+			"operator": self.operator,
+			"from_time": self.from_time,
+			"to_time": self.to_time,
+			"stop_reason": "Machine malfunction",
+		}
+		values.update(extra)
+		return frappe.get_doc(values).insert()
+
+	def run_report(self, **extra):
+		filters = frappe._dict(
+			{
+				"from_date": add_days(today(), -1),
+				"to_date": add_days(today(), 1),
+			}
+		)
+		filters.update(extra)
+		return execute(filters)[1]
+
+	def row_for_entry(self, rows, name):
+		return next((row for row in rows if row.get("name") == name), None)
+
+	def test_downtime_is_computed_in_hours(self):
+		# validate() stores downtime in minutes; the report converts it to hours.
+		self.assertEqual(self.entry.downtime, 120)
+
+		row = self.row_for_entry(self.run_report(), self.entry.name)
+		self.assertIsNotNone(row, "Downtime Entry not present in report output")
+		self.assertEqual(row.get("workstation"), self.workstation)
+		self.assertEqual(row.get("operator"), self.operator)
+		self.assertEqual(row.get("stop_reason"), "Machine malfunction")
+		self.assertEqual(row.get("downtime"), 2.0)
+
+	def test_workstation_filter_scopes_rows(self):
+		other = self.make_downtime_entry(self.other_workstation)
+
+		rows = self.run_report(workstation=self.workstation)
+		names = {row.get("name") for row in rows}
+		self.assertIn(self.entry.name, names)
+		self.assertNotIn(other.name, names)
+		self.assertTrue(all(row.get("workstation") == self.workstation for row in rows))
+
+	def test_date_range_excludes_out_of_window_entries(self):
+		# The report filters from_time >= from_date and to_time <= to_date; a window
+		# ending before the entry's from_time must exclude it.
+		rows = self.run_report(from_date=add_days(today(), -10), to_date=add_days(today(), -5))
+		self.assertIsNone(self.row_for_entry(rows, self.entry.name))
+
+	def test_chart_aggregates_downtime_per_workstation(self):
+		self.make_downtime_entry(self.workstation)
+
+		chart = execute(
+			frappe._dict(
+				{
+					"from_date": add_days(today(), -1),
+					"to_date": add_days(today(), 1),
+					"workstation": self.workstation,
+				}
+			)
+		)[3]
+
+		self.assertIn(self.workstation, chart["data"]["labels"])
+		index = chart["data"]["labels"].index(self.workstation)
+		# Two entries of 2 hours each for this workstation -> 4 hours aggregated.
+		self.assertEqual(chart["data"]["datasets"][0]["values"][index], 4.0)