diff --git a/application/Device/Device.php b/application/Device/Device.php
index 178f165fc..fa4186f27 100644
--- a/application/Device/Device.php
+++ b/application/Device/Device.php
@@ -15,25 +15,42 @@ class Device extends mfBaseModel
                 return null;
             }
 
-            if ($name == "creator") {
-                $this->creator = new User($this->create_by);
+            if($name == "creator") {
+                $this->creator = mfValuecache::singleton()->get("Worker-id-".$this->create_by);
+                if($this->creator === null) {
+                    $this->creator = new User($this->create_by);
+                    if($this->creator->id) {
+                        mfValuecache::singleton()->set("Worker-id-".$this->create_by, $this->creator);
+                    }
+                }
                 return $this->creator;
             }
 
-            if ($name == "editor") {
-                $this->editor = new User($this->edit_by);
+            if($name == "editor") {
+                $this->editor = mfValuecache::singleton()->get("Worker-id-".$this->edit_by);
+                if($this->editor === null) {
+                    $this->editor = new User($this->edit_by);
+                    if($this->editor->id) {
+                        mfValuecache::singleton()->set("Worker-id-".$this->edit_by, $this->editor);
+                    }
+                }
                 return $this->editor;
             }
 
             $classname = ucfirst($name);
-            $idfield = $name . "_id";
-            $this->$name = new $classname($this->$idfield);
+            $idfield = $name."_id";
+            $this->$name = mfValuecache::singleton()->get("mfObjectmodel-$name-".$this->$idfield);
+            if(!$this->$name) {
+                $this->$name = new $classname($this->$idfield);
+            }
 
-            if ($this->$name->id) {
+            if($this->$name->id) {
+                mfValuecache::singleton()->set("mfObjectmodel-$name-".$this->$name->id, $this->$name);
                 return $this->$name;
             } else {
                 return null;
             }
+
         }
 
         return $this->$name;
diff --git a/application/Devicetype/Devicetype.php b/application/Devicetype/Devicetype.php
index 7d8defcca..3e585bcec 100644
--- a/application/Devicetype/Devicetype.php
+++ b/application/Devicetype/Devicetype.php
@@ -15,24 +15,41 @@ class Devicetype extends mfBaseModel
             }
 
             if ($name == "creator") {
-                $this->creator = new User($this->create_by);
+                $this->creator = mfValuecache::singleton()->get("Worker-id-" . $this->create_by);
+                if ($this->creator === null) {
+                    $this->creator = new User($this->create_by);
+                    if ($this->creator->id) {
+                        mfValuecache::singleton()->set("Worker-id-" . $this->create_by, $this->creator);
+                    }
+                }
                 return $this->creator;
             }
 
             if ($name == "editor") {
-                $this->editor = new User($this->edit_by);
+                $this->editor = mfValuecache::singleton()->get("Worker-id-" . $this->edit_by);
+                if ($this->editor === null) {
+                    $this->editor = new User($this->edit_by);
+                    if ($this->editor->id) {
+                        mfValuecache::singleton()->set("Worker-id-" . $this->edit_by, $this->editor);
+                    }
+                }
                 return $this->editor;
             }
 
             $classname = ucfirst($name);
             $idfield = $name . "_id";
-            $this->$name = new $classname($this->$idfield);
+            $this->$name = mfValuecache::singleton()->get("mfObjectmodel-$name-" . $this->$idfield);
+            if (!$this->$name) {
+                $this->$name = new $classname($this->$idfield);
+            }
 
             if ($this->$name->id) {
+                mfValuecache::singleton()->set("mfObjectmodel-$name-" . $this->$name->id, $this->$name);
                 return $this->$name;
             } else {
                 return null;
             }
+
         }
 
         return $this->$name;