// get selected model element
		final EObject modelElement = getSelectedModelElement(event);
		if (modelElement == null) {
			return null;
		}
				
		Job job = new Job("ForceValidation") {
			@Override
			protected IStatus run(IProgressMonitor monitor) {
				// get the project manager instance (must use non-API method as 
				// the method notifyObjectsChanged is not exposed by the interface
				ECPProjectManagerImpl projectManager = (ECPProjectManagerImpl) ECPUtil.getECPProjectManager();

				// create a list with the selected object and all its children
				Collection<Object> objects = new HashSet<Object>();
				objects.add(modelElement);
				TreeIterator<Object> iterator = EcoreUtil.getAllContents(modelElement, true);
				while (iterator.hasNext()) {
					objects.add(iterator.next());
			    }

				// get the project of the selected element
				ECPProject project = projectManager.getProject(modelElement);
				
				// trigger the observers (fake object change)
				projectManager.notifyObjectsChanged(project, objects, false);				

				return Status.OK_STATUS;
			}
		};

		// Start the Job
		job.schedule(); 		

	private class ValidationObserver implements ECPProjectContentChangedObserver {
				
		/** {@inheritDoc} **/
		public Collection<Object> objectsChanged(ECPProject project, Collection<Object> objects) {
						
			// check if first object is a model object (not a project or something else)
			Object object = objects.iterator().next();
			if (!(object instanceof EObject)) {
				return new HashSet<Object>();
			}
			
			// step up the tree and get the top level element
			EObject topLevelElement = (EObject) object;
			while (!(topLevelElement.eContainer() instanceof Project)) {
				if (topLevelElement.eContainer() == null) {
					return new HashSet<Object>(); // just for safety => should never happen
				}
				topLevelElement = topLevelElement.eContainer();
			}				

			// create a list with all children of the object's top-level ancestor
			Collection<EObject> allElements = new HashSet<EObject>();
			TreeIterator<Object> iterator = EcoreUtil.getAllContents(topLevelElement, true);
			while (iterator.hasNext()) {
				EObject obj = (EObject)iterator.next();
				allElements.add(obj);					
			}

			// (re-) validate the top level element and all it's children => get a list of updated elements 
			Collection<EObject> updatedElements = getValidationService(project).validate(allElements);
						
			// return list of updated elements => this triggers update of their decorators in the Model Explorer tree
			return new HashSet<Object>(updatedElements);
		}
	}

ECPProjectManagerImpl projectManager = (ECPProjectManagerImpl) ECPUtil.getECPProjectManager();
projectManager.notifyObjectsChanged(project, objects, false);

ECPUtil.getECPObserverBus().notify(ECPProjectContentTouchedObserver.class)
			.contentTouched(project, toUpdate, structural);

	/**
	 * Project change observer that validates all (!) objects.
	 */
	private class ValidationObserver implements ECPProjectContentChangedObserver {
		
		/** {@inheritDoc} **/
		public Collection<Object> objectsChanged(ECPProject project, Collection<Object> objects) {
						
			// check if first object is a model object (not a project or something else)
			Object object = objects.iterator().next();
			if (!(object instanceof EObject)) {
				return new HashSet<Object>();
			}
			
			// step up the tree and get the top level element
			EObject topLevelElement = (EObject) object;
			while (!(topLevelElement.eContainer() instanceof Project)) {
				if (topLevelElement.eContainer() == null) {
					return new HashSet<Object>(); // just for safety => should never happen
				}
				topLevelElement = topLevelElement.eContainer();
			}				

			// create a list with all children of the object's top-level ancestor
			Collection<EObject> allElements = new HashSet<EObject>();
			TreeIterator<Object> iterator = EcoreUtil.getAllContents(topLevelElement, true);
			while (iterator.hasNext()) {
				EObject obj = (EObject)iterator.next();
				allElements.add(obj);	
				// trigger a validation notification for all objects => triggers the update of the 
				// validation decorations of the open editors
				obj.eNotify(new ValidationNotification(obj));
			}

			// (re-) validate the top level element and all it's children 
			// => returns a list of affected elements (by up-propagation) 
			Collection<EObject> affactedElements = getValidationService(project).validate(allElements);
						
			return new HashSet<Object>();
		}
	}