diff --git a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/InsertionDataUpdater.java b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/InsertionDataUpdater.java
index 8d019e2c..c065084d 100644
--- a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/InsertionDataUpdater.java
+++ b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/InsertionDataUpdater.java
@@ -62,12 +62,9 @@ class InsertionDataUpdater {
     }
 
     static Comparator<VersionedInsertionData> getComparator(){
-        return new Comparator<VersionedInsertionData>() {
-            @Override
-            public int compare(VersionedInsertionData o1, VersionedInsertionData o2) {
-                if(o1.getiData().getInsertionCost() < o2.getiData().getInsertionCost()) return -1;
-                return 1;
-            }
+        return (o1, o2) -> {
+            if (o1.getiData().getInsertionCost() < o2.getiData().getInsertionCost()) return -1;
+            return 1;
         };
     }
 
@@ -161,7 +158,7 @@ class InsertionDataUpdater {
         return bestScoredJob;
     }
 
-    static double score(Job unassignedJob, InsertionData best, InsertionData secondBest, ScoringFunction scoringFunction) {
+    private static double score(Job unassignedJob, InsertionData best, InsertionData secondBest, ScoringFunction scoringFunction) {
         return Scorer.score(unassignedJob,best,secondBest,scoringFunction);
     }
 
diff --git a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/RegretInsertionConcurrent.java b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/RegretInsertionConcurrent.java
index b71ac5ab..e4d03376 100644
--- a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/RegretInsertionConcurrent.java
+++ b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/recreate/RegretInsertionConcurrent.java
@@ -29,7 +29,10 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
-import java.util.concurrent.*;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorCompletionService;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
 
 /**
  * Insertion based on regret approach.
@@ -68,7 +71,7 @@ public class RegretInsertionConcurrent extends AbstractInsertionStrategy {
         this.scoringFunction = new DefaultScorer(vehicleRoutingProblem);
         this.insertionCostsCalculator = jobInsertionCalculator;
         this.vrp = vehicleRoutingProblem;
-        completionService = new ExecutorCompletionService<ScoredJob>(executorService);
+        completionService = new ExecutorCompletionService<>(executorService);
         logger.debug("initialise " + this);
     }
 
@@ -87,7 +90,7 @@ public class RegretInsertionConcurrent extends AbstractInsertionStrategy {
      */
     @Override
     public Collection<Job> insertUnassignedJobs(Collection<VehicleRoute> routes, Collection<Job> unassignedJobs) {
-        List<Job> badJobs = new ArrayList<Job>(unassignedJobs.size());
+        List<Job> badJobs = new ArrayList<>(unassignedJobs.size());
 
         Iterator<Job> jobIterator = unassignedJobs.iterator();
         while (jobIterator.hasNext()){
@@ -135,14 +138,7 @@ public class RegretInsertionConcurrent extends AbstractInsertionStrategy {
         ScoredJob bestScoredJob = null;
 
         for (final Job unassignedJob : unassignedJobList) {
-            completionService.submit(new Callable<ScoredJob>() {
-
-                @Override
-                public ScoredJob call() throws Exception {
-                    return RegretInsertion.getScoredJob(routes, unassignedJob, insertionCostsCalculator, scoringFunction);
-                }
-
-            });
+            completionService.submit(() -> RegretInsertion.getScoredJob(routes, unassignedJob, insertionCostsCalculator, scoringFunction));
         }
 
         try {