diff --git a/dhp-workflows/dhp-dedup-openaire/src/main/java/eu/dnetlib/dhp/oa/dedup/model/BlockStats.java b/dhp-workflows/dhp-dedup-openaire/src/main/java/eu/dnetlib/dhp/oa/dedup/model/BlockStats.java
index ef8505e8f..be4ec51a0 100644
--- a/dhp-workflows/dhp-dedup-openaire/src/main/java/eu/dnetlib/dhp/oa/dedup/model/BlockStats.java
+++ b/dhp-workflows/dhp-dedup-openaire/src/main/java/eu/dnetlib/dhp/oa/dedup/model/BlockStats.java
@@ -1,6 +1,8 @@
 package eu.dnetlib.dhp.oa.dedup.model;
 
-public class BlockStats {
+import java.io.Serializable;
+
+public class BlockStats implements Serializable {
 
     private String key; //key of the block
     private Long size; //number of elements in the block
diff --git a/dhp-workflows/dhp-dedup-openaire/src/test/java/eu/dnetlib/dhp/oa/dedup/SparkStatsTest.java b/dhp-workflows/dhp-dedup-openaire/src/test/java/eu/dnetlib/dhp/oa/dedup/SparkStatsTest.java
new file mode 100644
index 000000000..8fac56ef3
--- /dev/null
+++ b/dhp-workflows/dhp-dedup-openaire/src/test/java/eu/dnetlib/dhp/oa/dedup/SparkStatsTest.java
@@ -0,0 +1,175 @@
+package eu.dnetlib.dhp.oa.dedup;
+
+import eu.dnetlib.dhp.application.ArgumentApplicationParser;
+import eu.dnetlib.enabling.is.lookup.rmi.ISLookUpException;
+import eu.dnetlib.enabling.is.lookup.rmi.ISLookUpService;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+import org.apache.spark.SparkConf;
+import org.apache.spark.api.java.JavaSparkContext;
+import org.apache.spark.sql.SparkSession;
+import org.junit.jupiter.api.*;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.Serializable;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+
+import static java.nio.file.Files.createTempDirectory;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.lenient;
+
+@ExtendWith(MockitoExtension.class)
+public class SparkStatsTest implements Serializable {
+
+    @Mock(serializable = true)
+    ISLookUpService isLookUpService;
+
+    private static SparkSession spark;
+    private static JavaSparkContext jsc;
+
+    private static String testGraphBasePath;
+    private static String testOutputBasePath;
+    private static final String testActionSetId = "test-orchestrator";
+
+    @BeforeAll
+    public static void cleanUp() throws IOException, URISyntaxException {
+
+        testGraphBasePath = Paths
+                .get(SparkDedupTest.class.getResource("/eu/dnetlib/dhp/dedup/entities").toURI())
+                .toFile()
+                .getAbsolutePath();
+        testOutputBasePath = createTempDirectory(SparkDedupTest.class.getSimpleName() + "-")
+                .toAbsolutePath()
+                .toString();
+
+        FileUtils.deleteDirectory(new File(testOutputBasePath));
+
+        final SparkConf conf = new SparkConf();
+        conf.set("spark.sql.shuffle.partitions", "200");
+        spark = SparkSession
+                .builder()
+                .appName(SparkDedupTest.class.getSimpleName())
+                .master("local[*]")
+                .config(conf)
+                .getOrCreate();
+
+        jsc = JavaSparkContext.fromSparkContext(spark.sparkContext());
+    }
+
+    @BeforeEach
+    public void setUp() throws IOException, ISLookUpException {
+
+        lenient()
+                .when(isLookUpService.getResourceProfileByQuery(Mockito.contains(testActionSetId)))
+                .thenReturn(
+                        IOUtils
+                                .toString(
+                                        SparkDedupTest.class
+                                                .getResourceAsStream(
+                                                        "/eu/dnetlib/dhp/dedup/profiles/mock_orchestrator.xml")));
+
+        lenient()
+                .when(isLookUpService.getResourceProfileByQuery(Mockito.contains("organization")))
+                .thenReturn(
+                        IOUtils
+                                .toString(
+                                        SparkDedupTest.class
+                                                .getResourceAsStream(
+                                                        "/eu/dnetlib/dhp/dedup/conf/org.curr.conf.json")));
+
+        lenient()
+                .when(isLookUpService.getResourceProfileByQuery(Mockito.contains("publication")))
+                .thenReturn(
+                        IOUtils
+                                .toString(
+                                        SparkDedupTest.class
+                                                .getResourceAsStream(
+                                                        "/eu/dnetlib/dhp/dedup/conf/pub.curr.conf.json")));
+
+        lenient()
+                .when(isLookUpService.getResourceProfileByQuery(Mockito.contains("software")))
+                .thenReturn(
+                        IOUtils
+                                .toString(
+                                        SparkDedupTest.class
+                                                .getResourceAsStream(
+                                                        "/eu/dnetlib/dhp/dedup/conf/sw.curr.conf.json")));
+
+        lenient()
+                .when(isLookUpService.getResourceProfileByQuery(Mockito.contains("dataset")))
+                .thenReturn(
+                        IOUtils
+                                .toString(
+                                        SparkDedupTest.class
+                                                .getResourceAsStream(
+                                                        "/eu/dnetlib/dhp/dedup/conf/ds.curr.conf.json")));
+
+        lenient()
+                .when(isLookUpService.getResourceProfileByQuery(Mockito.contains("otherresearchproduct")))
+                .thenReturn(
+                        IOUtils
+                                .toString(
+                                        SparkDedupTest.class
+                                                .getResourceAsStream(
+                                                        "/eu/dnetlib/dhp/dedup/conf/orp.curr.conf.json")));
+    }
+
+    @Test
+    public void createBlockStatsTest() throws Exception {
+
+        ArgumentApplicationParser parser = new ArgumentApplicationParser(
+                IOUtils
+                        .toString(
+                                SparkCreateSimRels.class
+                                        .getResourceAsStream(
+                                                "/eu/dnetlib/dhp/oa/dedup/createBlockStats_parameters.json")));
+        parser
+                .parseArgument(
+                        new String[] {
+                                "-i", testGraphBasePath,
+                                "-asi", testActionSetId,
+                                "-la", "lookupurl",
+                                "-w", testOutputBasePath
+                        });
+
+        new SparkBlockStats(parser, spark).run(isLookUpService);
+
+        long orgs_blocks = spark
+                .read()
+                .textFile(testOutputBasePath + "/" + testActionSetId + "/organization_blockstats")
+                .count();
+
+        long pubs_blocks = spark
+                .read()
+                .textFile(testOutputBasePath + "/" + testActionSetId + "/publication_blockstats")
+                .count();
+
+        long sw_blocks = spark
+                .read()
+                .textFile(testOutputBasePath + "/" + testActionSetId + "/software_blockstats")
+                .count();
+
+        long ds_blocks = spark
+                .read()
+                .textFile(testOutputBasePath + "/" + testActionSetId + "/dataset_blockstats")
+                .count();
+
+        long orp_blocks = spark
+                .read()
+                .textFile(testOutputBasePath + "/" + testActionSetId + "/otherresearchproduct_blockstats")
+                .count();
+
+        assertEquals(121, orgs_blocks);
+        assertEquals(110, pubs_blocks);
+        assertEquals(21, sw_blocks);
+        assertEquals(67, ds_blocks);
+        assertEquals(55, orp_blocks);
+    }
+}
+