diff --git a/dnet-pace-core/pom.xml b/dnet-pace-core/pom.xml
index cb31ed689..d35fd68f1 100644
--- a/dnet-pace-core/pom.xml
+++ b/dnet-pace-core/pom.xml
@@ -1,70 +1,60 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+
 	<parent>
 		<groupId>eu.dnetlib</groupId>
-		<artifactId>dnet45-parent</artifactId>
-		<version>1.0.0</version>
-		<relativePath />
+		<artifactId>dnet-dedup</artifactId>
+		<version>3.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
 	</parent>
-	<modelVersion>4.0.0</modelVersion>
-	<groupId>eu.dnetlib</groupId>
+
 	<artifactId>dnet-pace-core</artifactId>
-	<packaging>jar</packaging>
-	<version>2.6.8-SNAPSHOT</version>
-	<scm>
-		<developerConnection>scm:svn:https://svn.driver.research-infrastructures.eu/driver/dnet45/modules/dnet-pace-core/trunk</developerConnection>
-	</scm>
+    <packaging>jar</packaging>
+
 	<dependencies>
 		<dependency>
 			<groupId>edu.cmu</groupId>
 			<artifactId>secondstring</artifactId>
-			<version>1.0.0</version>
 		</dependency>
 		<dependency>
 			<groupId>com.google.guava</groupId>
 			<artifactId>guava</artifactId>
-			<version>15.0</version>
 		</dependency>
 		<dependency>
 			<groupId>com.google.code.gson</groupId>
 			<artifactId>gson</artifactId>
-			<version>${google.gson.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>commons-lang</groupId>
 			<artifactId>commons-lang</artifactId>
-			<version>${commons.lang.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>commons-io</groupId>
 			<artifactId>commons-io</artifactId>
-			<version>${commons.io.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>commons-collections</groupId>
 			<artifactId>commons-collections</artifactId>
-			<version>${commons.collections.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>com.googlecode.protobuf-java-format</groupId>
 			<artifactId>protobuf-java-format</artifactId>
-			<version>1.2</version>
 		</dependency>
 		<dependency>
 			<groupId>org.antlr</groupId>
 			<artifactId>stringtemplate</artifactId>
-			<version>3.2</version>
 		</dependency>
 		<dependency>
 			<groupId>commons-logging</groupId>
 			<artifactId>commons-logging</artifactId>
-			<version>${commons.logging.version}</version>
 		</dependency>
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>${junit.version}</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
+
 </project>
diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/BlockProcessor.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/BlockProcessor.java
new file mode 100644
index 000000000..a9979f5ed
--- /dev/null
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/BlockProcessor.java
@@ -0,0 +1,199 @@
+package eu.dnetlib.pace.util;
+
+import com.google.common.collect.Lists;
+import eu.dnetlib.pace.clustering.NGramUtils;
+import eu.dnetlib.pace.config.DedupConfig;
+import eu.dnetlib.pace.config.WfConfig;
+import eu.dnetlib.pace.distance.PaceDocumentDistance;
+import eu.dnetlib.pace.distance.eval.ScoreResult;
+import eu.dnetlib.pace.model.Field;
+import eu.dnetlib.pace.model.MapDocument;
+import eu.dnetlib.pace.model.MapDocumentComparator;
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import java.util.*;
+
+public class BlockProcessor {
+
+    public static final List<String> accumulators= new ArrayList<>();
+
+    private static final Log log = LogFactory.getLog(BlockProcessor.class);
+
+    private DedupConfig dedupConf;
+
+
+    public static void constructAccumulator( final DedupConfig dedupConf) {
+        accumulators.add(String.format("%s::%s",dedupConf.getWf().getEntityType(), "records per hash key = 1"));
+        accumulators.add(String.format("%s::%s",dedupConf.getWf().getEntityType(), "missing " + dedupConf.getWf().getOrderField()));
+        accumulators.add(String.format("%s::%s",dedupConf.getWf().getEntityType(), String.format("Skipped records for count(%s) >= %s", dedupConf.getWf().getOrderField(), dedupConf.getWf().getGroupMaxSize())));
+        accumulators.add(String.format("%s::%s",dedupConf.getWf().getEntityType(), "skip list"));
+        accumulators.add(String.format("%s::%s",dedupConf.getWf().getEntityType(), "dedupSimilarity (x2)"));
+        accumulators.add(String.format("%s::%s",dedupConf.getWf().getEntityType(), "d < " + dedupConf.getWf().getThreshold()));
+    }
+
+    public BlockProcessor(DedupConfig dedupConf) {
+        this.dedupConf = dedupConf;
+    }
+
+    public void process(final String key, final Iterable<MapDocument> documents, final Reporter context)  {
+
+        final Queue<MapDocument> q = prepare(documents);
+
+        if (q.size() > 1) {
+            log.info("reducing key: '" + key + "' records: " + q.size());
+            //process(q, context);
+            process(simplifyQueue(q, key, context), context);
+        } else {
+            context.incrementCounter(dedupConf.getWf().getEntityType(), "records per hash key = 1", 1);
+        }
+    }
+
+    private Queue<MapDocument> prepare(final Iterable<MapDocument> documents) {
+        final Queue<MapDocument> queue = new PriorityQueue<>(100, new MapDocumentComparator(dedupConf.getWf().getOrderField()));
+
+        final Set<String> seen = new HashSet<String>();
+        final int queueMaxSize = dedupConf.getWf().getQueueMaxSize();
+
+        documents.forEach(doc -> {
+            if (queue.size() <= queueMaxSize) {
+                final String id = doc.getIdentifier();
+
+                if (!seen.contains(id)) {
+                    seen.add(id);
+                    queue.add(doc);
+                }
+            }
+        });
+
+        return queue;
+    }
+
+    private Queue<MapDocument> simplifyQueue(final Queue<MapDocument> queue, final String ngram, final Reporter context) {
+        final Queue<MapDocument> q = new LinkedList<>();
+
+        String fieldRef = "";
+        final List<MapDocument> tempResults = Lists.newArrayList();
+
+        while (!queue.isEmpty()) {
+            final MapDocument result = queue.remove();
+
+            final String orderFieldName = dedupConf.getWf().getOrderField();
+            final Field orderFieldValue = result.values(orderFieldName);
+            if (!orderFieldValue.isEmpty()) {
+                final String field = NGramUtils.cleanupForOrdering(orderFieldValue.stringValue());
+                if (field.equals(fieldRef)) {
+                    tempResults.add(result);
+                } else {
+                    populateSimplifiedQueue(q, tempResults, context, fieldRef, ngram);
+                    tempResults.clear();
+                    tempResults.add(result);
+                    fieldRef = field;
+                }
+            } else {
+                context.incrementCounter(dedupConf.getWf().getEntityType(), "missing " + dedupConf.getWf().getOrderField(), 1);
+            }
+        }
+        populateSimplifiedQueue(q, tempResults, context, fieldRef, ngram);
+
+        return q;
+    }
+
+    private void populateSimplifiedQueue(final Queue<MapDocument> q,
+                                         final List<MapDocument> tempResults,
+                                         final Reporter context,
+                                         final String fieldRef,
+                                         final String ngram) {
+        WfConfig wf = dedupConf.getWf();
+        if (tempResults.size() < wf.getGroupMaxSize()) {
+            q.addAll(tempResults);
+        } else {
+            context.incrementCounter(wf.getEntityType(), String.format("Skipped records for count(%s) >= %s", wf.getOrderField(), wf.getGroupMaxSize()), tempResults.size());
+            log.info("Skipped field: " + fieldRef + " - size: " + tempResults.size() + " - ngram: " + ngram);
+        }
+    }
+
+    private void process(final Queue<MapDocument> queue, final Reporter context)  {
+
+        final PaceDocumentDistance algo = new PaceDocumentDistance();
+
+        while (!queue.isEmpty()) {
+
+            final MapDocument pivot = queue.remove();
+            final String idPivot = pivot.getIdentifier();
+
+            WfConfig wf = dedupConf.getWf();
+            final Field fieldsPivot = pivot.values(wf.getOrderField());
+            final String fieldPivot = (fieldsPivot == null) || fieldsPivot.isEmpty() ? null : fieldsPivot.stringValue();
+
+            if (fieldPivot != null) {
+                // System.out.println(idPivot + " --> " + fieldPivot);
+
+                int i = 0;
+                for (final MapDocument curr : queue) {
+                    final String idCurr = curr.getIdentifier();
+
+                    if (mustSkip(idCurr)) {
+
+                        context.incrementCounter(wf.getEntityType(), "skip list", 1);
+
+                        break;
+                    }
+
+                    if (i > wf.getSlidingWindowSize()) {
+                        break;
+                    }
+
+                    final Field fieldsCurr = curr.values(wf.getOrderField());
+                    final String fieldCurr = (fieldsCurr == null) || fieldsCurr.isEmpty() ? null : fieldsCurr.stringValue();
+
+                    if (!idCurr.equals(idPivot) && (fieldCurr != null)) {
+
+                        final ScoreResult sr = similarity(algo, pivot, curr);
+                        log.info(sr.toString()+"SCORE "+ sr.getScore());
+                        emitOutput(sr, idPivot, idCurr, context);
+                        i++;
+                    }
+                }
+            }
+        }
+    }
+
+    private void emitOutput(final ScoreResult sr, final String idPivot, final String idCurr, final Reporter context)  {
+        final double d = sr.getScore();
+
+        if (d >= dedupConf.getWf().getThreshold()) {
+
+            writeSimilarity(context, idPivot, idCurr);
+            context.incrementCounter(dedupConf.getWf().getEntityType(), "dedupSimilarity (x2)", 1);
+        } else {
+            context.incrementCounter(dedupConf.getWf().getEntityType(), "d < " + dedupConf.getWf().getThreshold(), 1);
+        }
+    }
+
+    private ScoreResult similarity(final PaceDocumentDistance algo, final MapDocument a, final MapDocument b) {
+        try {
+            return algo.between(a, b, dedupConf);
+        } catch(Throwable e) {
+            log.error(String.format("\nA: %s\n----------------------\nB: %s", a, b), e);
+            throw new IllegalArgumentException(e);
+        }
+    }
+
+    private boolean mustSkip(final String idPivot) {
+        return dedupConf.getWf().getSkipList().contains(getNsPrefix(idPivot));
+    }
+
+    private String getNsPrefix(final String id) {
+        return StringUtils.substringBetween(id, "|", "::");
+    }
+
+    private void writeSimilarity(final Reporter context, final String from, final String to)  {
+        final String type = dedupConf.getWf().getEntityType();
+
+        context.emit(type, from, to);
+        context.emit(type, to, from);
+    }
+
+}
diff --git a/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/Reporter.java b/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/Reporter.java
new file mode 100644
index 000000000..10c886cb5
--- /dev/null
+++ b/dnet-pace-core/src/main/java/eu/dnetlib/pace/util/Reporter.java
@@ -0,0 +1,11 @@
+package eu.dnetlib.pace.util;
+
+
+import java.io.Serializable;
+
+public interface Reporter extends Serializable {
+
+    void incrementCounter(String counterGroup, String counterName, long delta);
+
+    void emit(String type, String from, String to);
+}