diff --git a/library/Businessprocess/BpNode.php b/library/Businessprocess/BpNode.php
index d9e91c4..f413c96 100644
--- a/library/Businessprocess/BpNode.php
+++ b/library/Businessprocess/BpNode.php
@@ -19,6 +19,7 @@ class BpNode extends Node
     protected $alias;
     protected $counters;
     protected $missing = null;
+    protected $missingChildren;
 
     protected static $emptyStateSummary = array(
         'OK'          => 0,
@@ -135,6 +136,25 @@ class BpNode extends Node
         return $this->missing;
     }
 
+    public function getMissingChildren()
+    {
+        if ($this->missingChildren === null) {
+            foreach ($this->getChildren() as $child) {
+                if ($child->isMissing()) {
+                    $missing[(string) $child] = $child;
+                }
+
+                foreach ($child->getMissingChildren() as $m) {
+                    $missing[(string) $m] = $m;
+                }
+            }
+
+            $this->missingChildren = $missing;
+        }
+
+        return $this->missingChildren;
+    }
+
     public function getOperator()
     {
         return $this->operator;
diff --git a/library/Businessprocess/Node.php b/library/Businessprocess/Node.php
index 4133b1c..3652454 100644
--- a/library/Businessprocess/Node.php
+++ b/library/Businessprocess/Node.php
@@ -127,6 +127,16 @@ abstract class Node
         return $this->missing;
     }
 
+    public function hasMissingChildren()
+    {
+        return count($this->getMissingChildren() > 0);
+    }
+
+    public function getMissingChildren()
+    {
+        return array();
+    }
+
     public function hasInfoUrl()
     {
         return false;
@@ -334,7 +344,11 @@ abstract class Node
         if ($this->isMissing()) {
             return array('missing');
         } elseif ($state === 'ok') {
-            return array('ok');
+            if ($this->hasMissingChildren()) {
+                return array('ok', 'missing-children');
+            } else {
+                return array('ok');
+            }
         } else {
             return array('problem', $state);
         }