diff --git a/dhp-common/pom.xml b/dhp-common/pom.xml
index 1dc3208b5..6e7ee527b 100644
--- a/dhp-common/pom.xml
+++ b/dhp-common/pom.xml
@@ -29,6 +29,12 @@
 			<artifactId>spark-sql_2.11</artifactId>
 		</dependency>
 
+		<dependency>
+			<groupId>eu.dnetlib.dhp</groupId>
+			<artifactId>dhp-schemas</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+
 		<dependency>
 			<groupId>commons-cli</groupId>
 			<artifactId>commons-cli</artifactId>
diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java
new file mode 100644
index 000000000..02a946154
--- /dev/null
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/IdentifierFactory.java
@@ -0,0 +1,90 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import eu.dnetlib.dhp.schema.oaf.OafEntity;
+import eu.dnetlib.dhp.schema.oaf.StructuredProperty;
+import eu.dnetlib.dhp.utils.DHPUtils;
+import org.apache.commons.lang.StringUtils;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.Serializable;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * Factory class for OpenAIRE identifiers in the Graph
+ */
+public class IdentifierFactory implements Serializable {
+
+	private static final Logger log = LoggerFactory.getLogger(IdentifierFactory.class);
+
+	public static final String ID_SEPARATOR = "::";
+	public static final String ID_PREFIX_SEPARATOR = "|";
+	public final static String ID_REGEX = "^[0-9][0-9]\\"+ID_PREFIX_SEPARATOR+".{12}"+ID_SEPARATOR+"[a-zA-Z0-9]{32}$";
+	public static final int ID_PREFIX_LEN = 12;
+
+	public static Set<String> acceptedPidTypes = new HashSet<>();
+
+	static {
+		acceptedPidTypes.add("doi");
+		acceptedPidTypes.add("doi");
+		acceptedPidTypes.add("doi");
+		acceptedPidTypes.add("doi");
+		acceptedPidTypes.add("doi");
+		acceptedPidTypes.add("doi");
+
+	}
+
+	public static <T extends OafEntity> String createIdentifier(T entity) {
+
+		if (Objects.isNull(entity.getPid()) || entity.getPid().isEmpty()) {
+			return entity.getId();
+		}
+
+		return entity
+				.getPid()
+				.stream()
+				.filter(s -> Objects.nonNull(s.getQualifier()))
+				.filter(s -> acceptedPidTypes.contains(s.getQualifier().getClassid()))
+				.max(new PidComparator<T>(entity))
+				.map(s -> idFromPid(entity, s))
+				.map(IdentifierFactory::verifyIdSyntax)
+				.orElseGet(entity::getId);
+	}
+
+	protected static String verifyIdSyntax(String s) {
+		if(StringUtils.isBlank(s) || !s.matches(ID_REGEX)) {
+			throw new RuntimeException(String.format("malformed id: '%s'", s));
+		} else {
+			return s;
+		}
+	}
+
+	private static <T extends OafEntity> String idFromPid(T entity, StructuredProperty s) {
+		return new StringBuilder()
+				.append(StringUtils.substringBefore(entity.getId(), ID_PREFIX_SEPARATOR))
+				.append(ID_PREFIX_SEPARATOR)
+				.append(createPrefix(s.getQualifier().getClassid()))
+				.append(ID_SEPARATOR)
+				.append(DHPUtils.md5(normalizePidValue(s.getValue())))
+				.toString();
+	}
+
+	private static String normalizePidValue(String value) {
+		//TODO more aggressive cleaning? keep only alphanum and punctation?
+		return value.toLowerCase().replaceAll(" ", "");
+	}
+
+	// create the prefix (length = 12)
+	private static String createPrefix(String pidType) {
+		StringBuilder prefix = new StringBuilder(StringUtils.left(pidType, ID_PREFIX_LEN));
+		while (prefix.length() < ID_PREFIX_LEN) {
+			prefix.append("_");
+		}
+		return prefix.substring(0, ID_PREFIX_LEN);
+	}
+
+}
diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidComparator.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidComparator.java
new file mode 100644
index 000000000..97bdd9c77
--- /dev/null
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/PidComparator.java
@@ -0,0 +1,84 @@
+
+package eu.dnetlib.dhp.schema.oaf.utils;
+
+import java.util.Comparator;
+
+import eu.dnetlib.dhp.schema.common.ModelSupport;
+import eu.dnetlib.dhp.schema.oaf.OafEntity;
+import eu.dnetlib.dhp.schema.oaf.Organization;
+import eu.dnetlib.dhp.schema.oaf.Result;
+import eu.dnetlib.dhp.schema.oaf.StructuredProperty;
+
+public class PidComparator<T extends OafEntity> implements Comparator<StructuredProperty> {
+
+	private T entity;
+
+	public PidComparator(T entity) {
+		this.entity = entity;
+	}
+
+	@Override
+	public int compare(StructuredProperty left, StructuredProperty right) {
+
+		if (left == null && right == null)
+			return 0;
+		if (left == null)
+			return 1;
+		if (right == null)
+			return -1;
+
+		String lClass = left.getQualifier().getClassid();
+		String rClass = right.getQualifier().getClassid();
+
+		if (lClass.equals(rClass))
+			return 0;
+
+		if (ModelSupport.isSubClass(entity, Result.class)) {
+			return compareResultPids(lClass, rClass);
+		}
+		if (ModelSupport.isSubClass(entity, Organization.class)) {
+			return compareOrganizationtPids(lClass, rClass);
+		}
+
+		// Else (but unlikely), lexicographical ordering will do.
+		return lClass.compareTo(rClass);
+	}
+
+	private int compareResultPids(String lClass, String rClass) {
+		if (lClass.equals("doi"))
+			return -1;
+		if (rClass.equals("doi"))
+			return 1;
+
+		if (lClass.equals("pmid"))
+			return -1;
+		if (rClass.equals("pmid"))
+			return 1;
+
+		if (lClass.equals("pmc"))
+			return -1;
+		if (rClass.equals("pmc"))
+			return 1;
+
+		return 0;
+	}
+
+	private int compareOrganizationtPids(String lClass, String rClass) {
+		if (lClass.equals("GRID"))
+			return -1;
+		if (rClass.equals("GRID"))
+			return 1;
+
+		if (lClass.equals("mag_id"))
+			return -1;
+		if (rClass.equals("mag_id"))
+			return 1;
+
+		if (lClass.equals("urn"))
+			return -1;
+		if (rClass.equals("urn"))
+			return 1;
+
+		return 0;
+	}
+}