diff --git a/tests/make_failure_report.sh b/tests/make_failure_report.sh
index b30e43892ac..aa07fad2f15 100755
--- a/tests/make_failure_report.sh
+++ b/tests/make_failure_report.sh
@@ -6,6 +6,7 @@ OPM_TESTS_ROOT=$1
 BUILD_DIR=$2
 RESULT_DIR=$3
 SOURCE_DIR=`dirname "$0"`
+JOBS=${BUILDTHREADS:-16}
 
 FAILED_TESTS=`cat $BUILD_DIR/Testing/Temporary/LastTestsFailed*.log`
 
@@ -13,6 +14,7 @@ mkdir -p $BUILD_DIR/failure_report
 cd $BUILD_DIR/failure_report
 rm -f *
 
+JOBLIST=""
 for failed_test in $FAILED_TESTS
 do
   if grep -q -E "compareECLFiles" <<< $failed_test
@@ -23,8 +25,7 @@ do
     dir_name=$(awk -v search="set_tests_properties\\\($failed_test\$" -v prop="DIRNAME" -f ${SOURCE_DIR}/getprop.awk $RESULT_DIR/CTestTestfile.cmake)
     file_name=$(awk -v search="set_tests_properties\\\($failed_test\$" -v prop="FILENAME" -f ${SOURCE_DIR}/getprop.awk $RESULT_DIR/CTestTestfile.cmake)
     test_name=$(awk -v search="set_tests_properties\\\($failed_test\$" -v prop="TESTNAME" -f ${SOURCE_DIR}/getprop.awk $RESULT_DIR/CTestTestfile.cmake)
-    echo "Processing ${test_name}"
-    $SOURCE_DIR/plot_well_comparison.py -r $OPM_TESTS_ROOT/$dir_name/opm-simulation-reference/$binary/$file_name -s $RESULT_DIR/tests/results/$binary+$test_name/$file_name -c $test_name -o plot
+    JOBLIST+="-r $OPM_TESTS_ROOT/$dir_name/opm-simulation-reference/$binary/$file_name -s $RESULT_DIR/tests/results/$binary+$test_name/$file_name -c $test_name -o plot\\n"
   elif grep -q -E "compareSeparateECLFiles" <<< $failed_test
   then
     failed_test=`echo $failed_test | sed -e 's/.*://g' -e 's/\+/./g'`
@@ -34,11 +35,12 @@ do
     file_name1=$(awk -v search="set_tests_properties\\\($failed_test\$" -v prop="FILENAME1" -f ${SOURCE_DIR}/getprop.awk $RESULT_DIR/CTestTestfile.cmake)
     file_name2=$(awk -v search="set_tests_properties\\\($failed_test\$" -v prop="FILENAME2" -f ${SOURCE_DIR}/getprop.awk $RESULT_DIR/CTestTestfile.cmake)
     test_name=$(awk -v search="set_tests_properties\\\($failed_test\$" -v prop="TESTNAME" -f ${SOURCE_DIR}/getprop.awk $RESULT_DIR/CTestTestfile.cmake)
-    echo "Processing ${test_name}"
-    $SOURCE_DIR/plot_well_comparison.py -r $RESULT_DIR/tests/results/$binary+$test_name/$file_name1 -s $RESULT_DIR/tests/results/$binary+$test_name/$file_name2 -c $test_name -o plot -t "$file_name1" -u "$file_name2"
+    JOBLIST+="-r $RESULT_DIR/tests/results/$binary+$test_name/$file_name1 -s $RESULT_DIR/tests/results/$binary+$test_name/$file_name2 -c $test_name -o plot -t $file_name1 -u $file_name2\\n"
   fi
 done
 
+echo -e $JOBLIST | xargs -L1 -P${JOBS} $SOURCE_DIR/plot_well_comparison.py
+
 if test -n "$FAILED_TESTS"
 then
   $SOURCE_DIR/plot_well_comparison.py  -o rename
diff --git a/tests/plot_well_comparison.py b/tests/plot_well_comparison.py
index 30a2a55b721..382ab382819 100755
--- a/tests/plot_well_comparison.py
+++ b/tests/plot_well_comparison.py
@@ -5,6 +5,7 @@
 
 import argparse
 from datetime import datetime, timedelta
+from filelock import FileLock
 import matplotlib.pyplot as plt
 from matplotlib.dates import DateFormatter
 from matplotlib.backends.backend_pdf import PdfPages
@@ -84,16 +85,18 @@ def run_analysis(ref_file_name, sys_file_name, test_name, ref_name, sim_name):
     p.close()
 
     if os.path.exists('max_devs.pkl'):
-        with open('max_devs.pkl', 'rb') as f:
-            max_deviations = pickle.load(f)
+        with FileLock('max_devs.lck'):
+            with open('max_devs.pkl', 'rb') as f:
+                max_deviations = pickle.load(f)
     else:
         max_deviations = {}
 
     max_dev = max(deviation, key = lambda x: deviation[x])
     max_deviations[test_name] = deviation[max_dev]
 
-    with open('max_devs.pkl', 'wb') as f:
-        pickle.dump(max_deviations, f)
+    with FileLock('max_devs.lck'):
+        with open('max_devs.pkl', 'wb') as f:
+            pickle.dump(max_deviations, f)
 
 # Rename files to rank them according to maximum deviations
 def reorder_files():
@@ -117,6 +120,7 @@ def reorder_files():
 args = parser.parse_args()
 
 if args.operation == 'plot':
+    print(f"Processing {args.test_name}")
     run_analysis(args.ref_file, args.sim_file, args.test_name, args.ref_name, args.sim_name)
 else:
     reorder_files()