diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialCategoryDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialCategoryDAO.java
index 303a1a91a..cc4dfe1b8 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialCategoryDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialCategoryDAO.java
@@ -22,7 +22,7 @@ package org.navalplanner.business.materials.daos;
 
 import java.util.List;
 
-import org.navalplanner.business.common.daos.IGenericDAO;
+import org.navalplanner.business.common.daos.IIntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.materials.entities.Material;
 import org.navalplanner.business.materials.entities.MaterialCategory;
@@ -33,7 +33,8 @@ import org.navalplanner.business.materials.entities.MaterialCategory;
  * @author Jacobo Aragunde Perez <jaragunde@igalia.com>
  * @author Diego Pino Garcia <dpino@igalia.com>
  */
-public interface IMaterialCategoryDAO extends IGenericDAO<MaterialCategory, Long> {
+public interface IMaterialCategoryDAO extends
+        IIntegrationEntityDAO<MaterialCategory> {
 
     /**
      * Returns true if {@link MaterialCategory} exists
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialDAO.java
index b62d7bd85..3808c559d 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/IMaterialDAO.java
@@ -23,7 +23,7 @@ package org.navalplanner.business.materials.daos;
 import java.util.List;
 import java.util.Set;
 
-import org.navalplanner.business.common.daos.IGenericDAO;
+import org.navalplanner.business.common.daos.IIntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.materials.entities.Material;
 import org.navalplanner.business.materials.entities.MaterialAssignment;
@@ -37,7 +37,7 @@ import org.navalplanner.business.orders.entities.Order;
  * @author Jacobo Aragunde Perez <jaragunde@igalia.com>
  * @author Diego Pino Garcia <dpino@igalia.com>
  */
-public interface IMaterialDAO extends IGenericDAO<Material, Long> {
+public interface IMaterialDAO extends IIntegrationEntityDAO<Material> {
 
     /**
      * Returns true if {@link Material} exits
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialCategoryDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialCategoryDAO.java
index a46d45bca..f991cae28 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialCategoryDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialCategoryDAO.java
@@ -24,7 +24,7 @@ import java.util.List;
 
 import org.hibernate.Criteria;
 import org.hibernate.criterion.Restrictions;
-import org.navalplanner.business.common.daos.GenericDAOHibernate;
+import org.navalplanner.business.common.daos.IntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.materials.entities.MaterialCategory;
 import org.springframework.beans.factory.config.BeanDefinition;
@@ -40,7 +40,8 @@ import org.springframework.transaction.annotation.Transactional;
  */
 @Repository
 @Scope(BeanDefinition.SCOPE_SINGLETON)
-public class MaterialCategoryDAO extends GenericDAOHibernate<MaterialCategory, Long> implements
+public class MaterialCategoryDAO extends IntegrationEntityDAO<MaterialCategory>
+        implements
         IMaterialCategoryDAO {
 
     @Override
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialDAO.java
index ffacbcc89..c6ea30705 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/materials/daos/MaterialDAO.java
@@ -28,7 +28,7 @@ import java.util.Set;
 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.criterion.Restrictions;
-import org.navalplanner.business.common.daos.GenericDAOHibernate;
+import org.navalplanner.business.common.daos.IntegrationEntityDAO;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.materials.entities.Material;
 import org.navalplanner.business.materials.entities.MaterialAssignment;
@@ -50,7 +50,7 @@ import org.springframework.transaction.annotation.Transactional;
  */
 @Repository
 @Scope(BeanDefinition.SCOPE_SINGLETON)
-public class MaterialDAO extends GenericDAOHibernate<Material, Long> implements
+public class MaterialDAO extends IntegrationEntityDAO<Material> implements
         IMaterialDAO {
 
     @Override
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/Material.java b/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/Material.java
index ceef60bbb..966c74a3a 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/Material.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/Material.java
@@ -25,7 +25,7 @@ import java.math.BigDecimal;
 import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotEmpty;
 import org.hibernate.validator.NotNull;
-import org.navalplanner.business.common.BaseEntity;
+import org.navalplanner.business.common.IntegrationEntity;
 import org.navalplanner.business.common.Registry;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.materials.daos.IMaterialDAO;
@@ -36,7 +36,7 @@ import org.navalplanner.business.materials.daos.IMaterialDAO;
  * @author Jacobo Aragunde Perez <jaragunde@igalia.com>
  *
  */
-public class Material extends BaseEntity implements Comparable {
+public class Material extends IntegrationEntity implements Comparable {
 
     @NotEmpty(message = "code not specified")
     private String code;
@@ -146,4 +146,9 @@ public class Material extends BaseEntity implements Comparable {
         }
     }
 
+    @Override
+    protected IMaterialDAO getIntegrationEntityDAO() {
+        return Registry.getMaterialDAO();
+    }
+
 }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/MaterialCategory.java b/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/MaterialCategory.java
index 67a936a02..d014f727d 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/MaterialCategory.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/materials/entities/MaterialCategory.java
@@ -26,10 +26,12 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+
+import org.apache.commons.lang.StringUtils;
 import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotEmpty;
 import org.hibernate.validator.Valid;
-import org.navalplanner.business.common.BaseEntity;
+import org.navalplanner.business.common.IntegrationEntity;
 import org.navalplanner.business.common.Registry;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
 import org.navalplanner.business.materials.daos.IMaterialCategoryDAO;
@@ -40,7 +42,7 @@ import org.navalplanner.business.materials.daos.IMaterialCategoryDAO;
  * @author Jacobo Aragunde Perez <jaragunde@igalia.com>
  *
  */
-public class MaterialCategory extends BaseEntity {
+public class MaterialCategory extends IntegrationEntity {
 
     public static List<Material> getAllMaterialsFrom(
             Collection<? extends MaterialCategory> categories) {
@@ -144,4 +146,26 @@ public class MaterialCategory extends BaseEntity {
         }
     }
 
+    public Material getMaterialByCode(String code)
+            throws InstanceNotFoundException {
+
+        if (StringUtils.isBlank(code)) {
+            throw new InstanceNotFoundException(code, Material.class.getName());
+        }
+
+        for (Material m : this.materials) {
+            if (m.getCode().equalsIgnoreCase(StringUtils.trim(code))) {
+                return m;
+            }
+        }
+
+        throw new InstanceNotFoundException(code, Material.class.getName());
+
+    }
+
+    @Override
+    protected IMaterialCategoryDAO getIntegrationEntityDAO() {
+        return Registry.getMaterialCategoryDAO();
+    }
+
 }
diff --git a/navalplanner-business/src/main/resources/org/navalplanner/business/materials/entities/Materials.hbm.xml b/navalplanner-business/src/main/resources/org/navalplanner/business/materials/entities/Materials.hbm.xml
index c2ec68ad4..0d4582908 100644
--- a/navalplanner-business/src/main/resources/org/navalplanner/business/materials/entities/Materials.hbm.xml
+++ b/navalplanner-business/src/main/resources/org/navalplanner/business/materials/entities/Materials.hbm.xml
@@ -49,6 +49,8 @@
     </id>
     <version name="version" access="property" type="long" />
 
+    <property name="code" access="property" not-null="true" unique="true"/>
+
     <property name="name" />
 
     <set name="subcategories" inverse="true" cascade="all-delete-orphan">
diff --git a/navalplanner-webapp/src/test/java/org/navalplanner/web/test/ws/orders/OrderElementServiceTest.java b/navalplanner-webapp/src/test/java/org/navalplanner/web/test/ws/orders/OrderElementServiceTest.java
index a674aff9f..29cdced63 100644
--- a/navalplanner-webapp/src/test/java/org/navalplanner/web/test/ws/orders/OrderElementServiceTest.java
+++ b/navalplanner-webapp/src/test/java/org/navalplanner/web/test/ws/orders/OrderElementServiceTest.java
@@ -109,6 +109,9 @@ public class OrderElementServiceTest {
     @Resource
     private IDataBootstrap materialCategoryBootstrap;
 
+    @Resource
+    private IDataBootstrap unitTypeBootstrap;
+
     @Resource
     private IDataBootstrap criterionsBootstrap;
 
@@ -119,6 +122,7 @@ public class OrderElementServiceTest {
         configurationBootstrap.loadRequiredData();
         materialCategoryBootstrap.loadRequiredData();
         criterionsBootstrap.loadRequiredData();
+        unitTypeBootstrap.loadRequiredData();
     }
 
     @Autowired
@@ -471,7 +475,7 @@ public class OrderElementServiceTest {
         List<ConstraintViolationDTO> constraintViolations = instanceConstraintViolationsList
                 .get(0).constraintViolations;
         // Mandatory fields: material code
-        assertThat(constraintViolations.size(), equalTo(1));
+        assertThat(constraintViolations.size(), equalTo(2));
         assertThat(constraintViolations.get(0).fieldName, mustEnd("code"));
 
         assertThat(orderDAO.getOrders().size(), equalTo(previous));