diff --git a/HLTrigger/Timer/scripts/mergeResourcesJson.py b/HLTrigger/Timer/scripts/mergeResourcesJson.py
new file mode 100755
index 0000000000000..e107c52d79d9e
--- /dev/null
+++ b/HLTrigger/Timer/scripts/mergeResourcesJson.py
@@ -0,0 +1,57 @@
+#! /usr/bin/env python3
+
+import sys
+import json
+
+usage = """Usage: mergeResourceJson.py FILE [FILE ...]
+
+Merge the content of multiple "resources.json" files produced by the FastTimerService,
+and print the result to standard output.
+
+Example:
+    mergeResourceJson.py step*/pid*/resources.json > resources.json
+"""
+ 
+def merge_into(metrics, data, dest):
+  dest["events"] += data["events"]
+  for metric in metrics:
+    dest[metric] += data[metric]
+
+
+if len(sys.argv) == 1:
+  print(usage)
+  sys.exit(1)
+
+if '-h' in sys.argv[1:] or '--help' in sys.argv[1:]:
+  print(usage)
+  sys.exit(0)
+
+with open(sys.argv[1]) as f:
+  output = json.load(f)
+
+metrics = [ label for resource in output["resources"] for label in resource ]
+
+datamap = { module["type"] + '|' + module["label"] : module for module in output["modules"] }
+
+for arg in sys.argv[2:]:
+  with open(arg) as f:
+    input = json.load(f)
+
+  if output["resources"] != input["resources"]:
+    print("Error: input files describe different metrics")
+    sys.exit(1)
+
+  if output["total"]["label"] != input["total"]["label"]:
+    print("Warning: input files describe different process names")
+  merge_into(metrics, input["total"], output["total"])
+
+  for module in input["modules"]:
+    key = module["type"] + '|' + module["label"]
+    if key in datamap:
+      merge_into(metrics, module, datamap[key])
+    else:
+      datamap[key] = module
+      output["modules"].append(datamap[key])
+
+json.dump(output, sys.stdout, indent = 2 )
+sys.stdout.write('\n')