diff --git a/jsprit-core/src/main/java/algorithms/RuinRadial.java b/jsprit-core/src/main/java/algorithms/RuinRadial.java
index 7b9c5edf..330f6a1a 100644
--- a/jsprit-core/src/main/java/algorithms/RuinRadial.java
+++ b/jsprit-core/src/main/java/algorithms/RuinRadial.java
@@ -38,7 +38,7 @@ import basics.route.VehicleRoute;
 
 /**
  * 
- * RuinStrategy that ruins the neighborhood of a randomly selected service. The size and the structure of the neighborhood is defined by 
+ * RuinStrategy that ruins the neighborhood of a randomly selected job. The size and the structure of the neighborhood is defined by 
  * the share of jobs to be removed and the distance between jobs (where distance not necessarily mean Euclidean distance but an arbitrary 
  * measure).
  * 
diff --git a/jsprit-core/src/main/java/basics/Shipment.java b/jsprit-core/src/main/java/basics/Shipment.java
index 2e89396f..fe45070e 100644
--- a/jsprit-core/src/main/java/basics/Shipment.java
+++ b/jsprit-core/src/main/java/basics/Shipment.java
@@ -133,7 +133,7 @@ public class Shipment implements Job{
 		return demand;
 	}
 
-	public int getDemand() {
+	public int getSize() {
 		return demand;
 	}
 
diff --git a/jsprit-core/src/main/java/basics/VehicleRoutingProblem.java b/jsprit-core/src/main/java/basics/VehicleRoutingProblem.java
index 78035117..dad31f6a 100644
--- a/jsprit-core/src/main/java/basics/VehicleRoutingProblem.java
+++ b/jsprit-core/src/main/java/basics/VehicleRoutingProblem.java
@@ -236,7 +236,10 @@ public class VehicleRoutingProblem {
 			if(job instanceof Service) { 
 				addService((Service) job);
 			}
-			else throw new IllegalStateException("job can only be a shipment or a service, but is instance of " + job.getClass());
+			else{
+				if(jobs.containsKey(job.getId())){ logger.warn("job " + job + " already in job list. overrides existing job."); }
+				jobs.put(job.getId(),job);
+			}
 			return this;
 		}
 
@@ -357,6 +360,10 @@ public class VehicleRoutingProblem {
 		public Collection<Service> getAddedServices(){
 			return Collections.unmodifiableCollection(services);
 		}
+		
+		public Collection<Job> getAddedJobs(){
+			return Collections.unmodifiableCollection(jobs.values());
+		}
 }
 	
 	/**
diff --git a/jsprit-core/src/test/java/basics/ShipmentTest.java b/jsprit-core/src/test/java/basics/ShipmentTest.java
index d33cab30..6313d8a5 100644
--- a/jsprit-core/src/test/java/basics/ShipmentTest.java
+++ b/jsprit-core/src/test/java/basics/ShipmentTest.java
@@ -1,5 +1,56 @@
 package basics;
 
-public class ShipmentTest {
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
+import org.junit.Test;
+
+import util.Coordinate;
+import basics.route.TimeWindow;
+
+public class ShipmentTest {
+	
+	@Test
+	public void whenTwoShipmentsHaveTheSameId_theyReferencesShouldBeUnEqual(){
+		Shipment one = Shipment.Builder.newInstance("s", 10).setPickupLocation("foo").
+				setDeliveryLocation("foofoo").setPickupServiceTime(10).setDeliveryServiceTime(20).build();
+		Shipment two = Shipment.Builder.newInstance("s", 10).setPickupLocation("foo").
+				setDeliveryLocation("foofoo").setPickupServiceTime(10).setDeliveryServiceTime(20).build();
+		
+		assertTrue(one != two);
+	}
+
+	@Test
+	public void whenTwoShipmentsHaveTheSameId_theyShouldBeEqual(){
+		Shipment one = Shipment.Builder.newInstance("s", 10).setPickupLocation("foo").
+				setDeliveryLocation("foofoo").setPickupServiceTime(10).setDeliveryServiceTime(20).build();
+		Shipment two = Shipment.Builder.newInstance("s", 10).setPickupLocation("foo").
+				setDeliveryLocation("foofoo").setPickupServiceTime(10).setDeliveryServiceTime(20).build();
+		
+		assertTrue(one.equals(two));
+	}
+
+	@Test
+	public void whenShipmentIsInstantiatedWithASizeOf10_theSizeShouldBe10(){
+		Shipment one = Shipment.Builder.newInstance("s", 10).setPickupLocation("foo").
+				setDeliveryLocation("foofoo").setPickupServiceTime(10).setDeliveryServiceTime(20).build();
+		assertEquals(10,one.getSize());
+	}
+	
+	@Test
+	public void whenShipmentIsDefined_itsFieldsShouldBeDefinedCorrectly(){
+		Shipment one = Shipment.Builder.newInstance("s", 10).setPickupLocation("foo").setPickupCoord(Coordinate.newInstance(0, 0)).setPickupServiceTime(1.0)
+				.setPickupTimeWindow(TimeWindow.newInstance(0.0, 1.0))
+				.setDeliveryLocation("foofoo").setDeliveryServiceTime(20).setDeliveryCoord(Coordinate.newInstance(1, 1)).
+				setDeliveryTimeWindow(TimeWindow.newInstance(1.0, 2.0)).build();
+		assertEquals("s",one.getId());
+		assertEquals(10,one.getSize());
+		assertEquals("foo",one.getPickupLocation());
+		assertEquals(0,one.getPickupCoord().getX(),0.01);
+		assertEquals(1.0,one.getPickupServiceTime(),0.01);
+		assertEquals("foofoo",one.getDeliveryLocation());
+		assertEquals(20.0,one.getDeliveryServiceTime(),0.01);
+		assertEquals(1.0,one.getDeliveryCoord().getX(),0.01);
+		assertEquals(1.0,one.getDeliveryTimeWindow().getStart(),0.01);
+	}
 }
diff --git a/jsprit-core/src/test/java/basics/VehicleRoutingProblemBuilderTest.java b/jsprit-core/src/test/java/basics/VehicleRoutingProblemBuilderTest.java
index b392f94b..dc712f1e 100644
--- a/jsprit-core/src/test/java/basics/VehicleRoutingProblemBuilderTest.java
+++ b/jsprit-core/src/test/java/basics/VehicleRoutingProblemBuilderTest.java
@@ -64,5 +64,20 @@ public class VehicleRoutingProblemBuilderTest {
 
 	}
 	
+	@Test
+	public void whenShipmentsAreAdded_theyShouldBePartOfTheProblem(){
+		Shipment s = Shipment.Builder.newInstance("s", 10).setPickupLocation("foofoo").setDeliveryLocation("foo").build();
+		Shipment s2 = Shipment.Builder.newInstance("s2", 100).setPickupLocation("foofoo").setDeliveryLocation("foo").build();
+		VehicleRoutingProblem.Builder vrpBuilder = VehicleRoutingProblem.Builder.newInstance();
+		vrpBuilder.addJob(s);
+		vrpBuilder.addJob(s2);
+		VehicleRoutingProblem vrp = vrpBuilder.build();
+		assertEquals(2,vrp.getJobs().size());
+		
+		Job j = vrp.getJobs().get("s");
+		assertEquals(s,j);
+		assertEquals(s2,vrp.getJobs().get("s2"));
+	}
+	
 
 }