diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocatable.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocatable.java
index 98e7c57c5..5f5048ec5 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocatable.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocatable.java
@@ -20,6 +20,8 @@
 
 package org.navalplanner.business.planner.entities;
 
+import org.joda.time.LocalDate;
+
 /**
  * This interface represents an object that can be do an allocation based on an
  * amount of {@link ResourcesPerDay}
@@ -27,4 +29,6 @@ package org.navalplanner.business.planner.entities;
  */
 public interface IAllocatable {
     public void allocate(ResourcesPerDay resourcesPerDay);
+
+    public IAllocateHoursOnInterval onInterval(LocalDate start, LocalDate end);
 }
\ No newline at end of file
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocateHoursOnInterval.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocateHoursOnInterval.java
new file mode 100644
index 000000000..34d7c7631
--- /dev/null
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/IAllocateHoursOnInterval.java
@@ -0,0 +1,24 @@
+/*
+ * This file is part of ###PROJECT_NAME###
+ *
+ * Copyright (C) 2009 Fundación para o Fomento da Calidade Industrial e
+ *                    Desenvolvemento Tecnolóxico de Galicia
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.navalplanner.business.planner.entities;
+
+public interface IAllocateHoursOnInterval {
+    void allocateHours(int hours);
+}
\ No newline at end of file
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java
index 6fe600654..c125057f9 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java
@@ -296,7 +296,32 @@ public abstract class ResourceAllocation<T extends DayAssignment> extends
             return result;
         }
 
-        void allocate(LocalDate startInclusive, LocalDate endExclusive, int hours) {
+        private class AllocateHoursOnInterval implements
+                IAllocateHoursOnInterval {
+
+            private final LocalDate start;
+            private final LocalDate end;
+
+            AllocateHoursOnInterval(LocalDate start, LocalDate end) {
+                Validate.isTrue(start.compareTo(end) <= 0,
+                        "the end must be equal or posterior than start");
+                this.start = start;
+                this.end = end;
+            }
+
+            public void allocateHours(int hours) {
+                allocate(start, end, hours);
+            }
+        }
+
+        @Override
+        public IAllocateHoursOnInterval onInterval(LocalDate start,
+                LocalDate end) {
+            return new AllocateHoursOnInterval(start, end);
+        }
+
+        private void allocate(LocalDate startInclusive, LocalDate endExclusive,
+                int hours) {
             Validate.isTrue(hours >= 0);
             Validate.isTrue(startInclusive.compareTo(endExclusive) <= 0,
                     "the end must be equal or posterior than start");
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SpecificResourceAllocation.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SpecificResourceAllocation.java
index 427995880..e2f7f1a47 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SpecificResourceAllocation.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SpecificResourceAllocation.java
@@ -123,29 +123,9 @@ public class SpecificResourceAllocation extends
         }
     }
 
-    public interface IAllocateHoursOnInterval {
-        void allocateHours(int hours);
-    }
-
-    private class AllocateHoursOnInterval implements IAllocateHoursOnInterval {
-
-        private final LocalDate start;
-        private final LocalDate end;
-
-        AllocateHoursOnInterval(LocalDate start, LocalDate end) {
-            this.start = start;
-            this.end = end;
-        }
-
-        public void allocateHours(int hours) {
-            new SpecificAssignmentsAllocation().allocate(start, end, hours);
-        }
-    }
-
+    @Override
     public IAllocateHoursOnInterval onInterval(LocalDate start, LocalDate end) {
-        Validate.isTrue(start.compareTo(end) <= 0,
-                "the end must be equal or posterior than start");
-        return new AllocateHoursOnInterval(start, end);
+        return new SpecificAssignmentsAllocation().onInterval(start, end);
     }
 
     @Override