diff --git a/SAS/TMSS/backend/src/tmss/tmssapp/adapters/reports.py b/SAS/TMSS/backend/src/tmss/tmssapp/adapters/reports.py
index 21e0b38342aba09ff1d00990bb245fbb93b8b7ad..f4569ce40a22a15bef1212ae0b95b11c215136bd 100644
--- a/SAS/TMSS/backend/src/tmss/tmssapp/adapters/reports.py
+++ b/SAS/TMSS/backend/src/tmss/tmssapp/adapters/reports.py
@@ -65,8 +65,34 @@ def _get_completion_level(cycle: models.Cycle):
 
 
 def _get_observation_hours_per_category(cycle: models.Cycle):
+    # TODO: Better define system unavailability and idle values.
+    result = {}
+    result['total_duration_A'], result['total_duration_B'], result['total_duration_failed'], result['total_duration_idle'] \
+        = timedelta(), timedelta(), timedelta(), timedelta()
+
+    # Get SUBs within prio A
+    subs_A = models.SchedulingUnitBlueprint.objects.filter(draft__scheduling_set__project__cycles=cycle.pk).filter(priority_queue='A')
+    for sub in subs_A:
+        if sub.status == 'finished':
+            result['total_duration_A'] += sub.duration
+        if sub.status == 'cancelled':
+            result['total_duration_failed'] += sub.duration
+        result['total_duration_idle'] += sub.duration   # TODO: Need to subtract other states.
+    # Get SUBs within prio B
+    subs_B = models.SchedulingUnitBlueprint.objects.filter(draft__scheduling_set__project__cycles=cycle.pk).filter(priority_queue='B')
+    for sub in subs_B:
+        if sub.status == 'finished':
+            result['total_duration_B'] += sub.duration
+        if sub.status == 'cancelled':
+            result['total_duration_failed'] += sub.duration
+        result['total_duration_idle'] += sub.duration   # TODO: Need to subtract other states.
+
+    result['total_duration_A'] = result['total_duration_A'].total_seconds()
+    result['total_duration_B'] = result['total_duration_B'].total_seconds()
+    result['total_duration_failed'] = result['total_duration_failed'].total_seconds()
+    result['total_duration_idle'] = result['total_duration_idle'].total_seconds()
 
-    return 0
+    return result
 
 
 def _get_weekly_efficiency(cycle: models.Cycle):