diff --git a/jsprit-core/src/main/java/jsprit/core/problem/vehicle/FiniteFleetManagerFactory.java b/jsprit-core/src/main/java/jsprit/core/problem/vehicle/FiniteFleetManagerFactory.java
index 51a783a0..6fa3e180 100644
--- a/jsprit-core/src/main/java/jsprit/core/problem/vehicle/FiniteFleetManagerFactory.java
+++ b/jsprit-core/src/main/java/jsprit/core/problem/vehicle/FiniteFleetManagerFactory.java
@@ -27,7 +27,6 @@ public class FiniteFleetManagerFactory implements VehicleFleetManagerFactory{
 
 	private Collection<Vehicle> vehicles;
 	
-
 	/**
 	 * Constucts the factory.
 	 *
@@ -40,9 +39,14 @@ public class FiniteFleetManagerFactory implements VehicleFleetManagerFactory{
 
 	/**
 	 * Creates the finite fleetmanager.
+	 * 
+	 * @return VehicleFleetManager
+	 * @throws IllegalStateManager if vehicles == null or vehicles.isEmpty()
 	 */
 	@Override
 	public VehicleFleetManager createFleetManager() {
+		if(vehicles == null) throw new IllegalStateException("vehicles is null. this must not be.");
+		if(vehicles.isEmpty()) throw new IllegalStateException("vehicle-collection is empty. this must not be");
 		return new VehicleFleetManagerImpl(vehicles);
 	}
 
diff --git a/jsprit-core/src/test/java/jsprit/core/problem/vehicle/FiniteVehicleFleetManagerFactoryTest.java b/jsprit-core/src/test/java/jsprit/core/problem/vehicle/FiniteVehicleFleetManagerFactoryTest.java
new file mode 100644
index 00000000..1958d036
--- /dev/null
+++ b/jsprit-core/src/test/java/jsprit/core/problem/vehicle/FiniteVehicleFleetManagerFactoryTest.java
@@ -0,0 +1,16 @@
+package jsprit.core.problem.vehicle;
+
+import java.util.Arrays;
+
+import static org.mockito.Mockito.*;
+import org.junit.Test;
+
+public class FiniteVehicleFleetManagerFactoryTest {
+	
+	@Test
+	public void whenFiniteVehicleManagerIsCreated_itShouldReturnCorrectManager(){
+		VehicleFleetManager vfm = new FiniteFleetManagerFactory(Arrays.asList(mock(Vehicle.class))).createFleetManager();
+		
+	}
+
+}
diff --git a/jsprit-core/src/test/java/jsprit/core/problem/vehicle/TestVehicleFleetManager.java b/jsprit-core/src/test/java/jsprit/core/problem/vehicle/TestVehicleFleetManagerImpl.java
similarity index 98%
rename from jsprit-core/src/test/java/jsprit/core/problem/vehicle/TestVehicleFleetManager.java
rename to jsprit-core/src/test/java/jsprit/core/problem/vehicle/TestVehicleFleetManagerImpl.java
index 52b636b3..6833be64 100644
--- a/jsprit-core/src/test/java/jsprit/core/problem/vehicle/TestVehicleFleetManager.java
+++ b/jsprit-core/src/test/java/jsprit/core/problem/vehicle/TestVehicleFleetManagerImpl.java
@@ -28,7 +28,7 @@ import jsprit.core.problem.vehicle.VehicleImpl;
 import jsprit.core.problem.vehicle.VehicleTypeImpl;
 import junit.framework.TestCase;
 
-public class TestVehicleFleetManager extends TestCase{
+public class TestVehicleFleetManagerImpl extends TestCase{
 	
 	VehicleFleetManager fleetManager;