diff --git a/Admin/Installer.php b/Admin/Installer.php
index fcc36ab..1ab405b 100755
--- a/Admin/Installer.php
+++ b/Admin/Installer.php
@@ -35,11 +35,12 @@ final class Installer extends InstallerAbstract
     /**
      * {@inheritdoc}
      */
+    /*
     public static function install(DatabasePool $dbPool, ModuleInfo $info, SettingsInterface $cfgHandler) : void
     {
         parent::install($dbPool, $info, $cfgHandler);
 
-        /*
+
         $interfaces = Directory::list(__DIR__ . '/../Interfaces', '.*interface\.json', true);
 
         foreach ($interfaces as $interface) {
@@ -47,6 +48,7 @@ final class Installer extends InstallerAbstract
             $exchange->load();
 
             InterfaceManagerMapper::create($exchange);
-        }*/
+        }
     }
+    */
 }
diff --git a/Interfaces/GSD/Importer.php b/Interfaces/GSD/Importer.php
index bf91740..8652191 100755
--- a/Interfaces/GSD/Importer.php
+++ b/Interfaces/GSD/Importer.php
@@ -62,6 +62,7 @@ use phpOMS\Localization\ISO639x1Enum;
 use phpOMS\Message\RequestAbstract;
 use phpOMS\System\File\Local\Directory;
 use phpOMS\Utils\IO\Zip\Zip;
+use Modules\ItemManagement\Models\ItemAttributeValue;
 
 /**
  * GSD import class
@@ -79,7 +80,7 @@ final class Importer extends ImporterAbstract
      * @var ConnectionAbstract
      * @since 1.0.0
      */
-    private ?ConnectionAbstract $remote = null;
+    private ConnectionAbstract $remote;
 
     /**
      * Account
@@ -412,9 +413,9 @@ final class Importer extends ImporterAbstract
     /**
      * Import articles
      *
-     * @param \DateTime $start  Start time (inclusive)
-     * @param \DateTime $end    End time (inclusive)
-     * @param array     $images Article images
+     * @param \DateTime $start Start time (inclusive)
+     * @param \DateTime $end   End time (inclusive)
+     * @param array     $files Article images
      *
      * @return void
      *
@@ -456,6 +457,8 @@ final class Importer extends ImporterAbstract
             $images = \array_merge($jpg, $png);
             $images = \array_diff($images, $imagesOld);
 
+            /** @var string[] $images */
+            /** @var string $image */
             foreach ($images as $image) {
                 $number = (int) \explode('.', $image)[0];
 
@@ -465,7 +468,7 @@ final class Importer extends ImporterAbstract
                 $media[$number]->setPath('/Modules/Media/Files/Modules/ItemManagement/Articles/Images/' . $image);
                 $media[$number]->setVirtualPath('/Modules/ItemManagement/Articles/Images');
                 $media[$number]->setExtension(\explode('.', $image)[1]);
-                $media[$number]->setSize(\filesize($imagePath . '/' . $image));
+                $media[$number]->setSize((int) \filesize($imagePath . '/' . $image));
                 $media[$number]->setCreatedBy(new NullAccount($this->account));
 
                 MediaMapper::create($media[$number]);
@@ -613,7 +616,7 @@ final class Importer extends ImporterAbstract
     /**
      * Create and get item attribute values
      *
-     * @param ItemAttributeType[] $itemAttributeType Attribute types
+     * @param ItemAttributeType[] $itemAttrType Attribute types
      *
      * @return ItemAttributeValue[]
      *
diff --git a/Interfaces/GSD/Model/GSDCostCenter.php b/Interfaces/GSD/Model/GSDCostCenter.php
index d70704d..d1ee33a 100755
--- a/Interfaces/GSD/Model/GSDCostCenter.php
+++ b/Interfaces/GSD/Model/GSDCostCenter.php
@@ -81,7 +81,7 @@ class GSDCostCenter implements \JsonSerializable
      */
     public function getCreatedAt() : \DateTimeImmutable
     {
-        return $this->createdAt ?? new \DateTime();
+        return $this->createdAt ?? new \DateTimeImmutable();
     }
 
     /**
diff --git a/Interfaces/GSD/Model/GSDCostObject.php b/Interfaces/GSD/Model/GSDCostObject.php
index eb5852c..80da2a3 100755
--- a/Interfaces/GSD/Model/GSDCostObject.php
+++ b/Interfaces/GSD/Model/GSDCostObject.php
@@ -81,7 +81,7 @@ class GSDCostObject implements \JsonSerializable
      */
     public function getCreatedAt() : \DateTimeImmutable
     {
-        return $this->createdAt ?? new \DateTime();
+        return $this->createdAt ?? new \DateTimeImmutable();
     }
 
     /**
diff --git a/Interfaces/GSD/Model/GSDCustomer.php b/Interfaces/GSD/Model/GSDCustomer.php
index 48ddccf..ddfdabd 100755
--- a/Interfaces/GSD/Model/GSDCustomer.php
+++ b/Interfaces/GSD/Model/GSDCustomer.php
@@ -24,12 +24,6 @@ namespace Modules\Exchange\Interfaces\GSD\Model;
  */
 class GSDCustomer
 {
-    /**
-     * ID.
-     *
-     * @var int
-     * @since 1.0.0
-     */
     public int $id = 0;
 
     public int $createdBy = 0;
diff --git a/Interfaces/GSD/Model/GSDCustomerMapper.php b/Interfaces/GSD/Model/GSDCustomerMapper.php
index 205442f..41dd073 100755
--- a/Interfaces/GSD/Model/GSDCustomerMapper.php
+++ b/Interfaces/GSD/Model/GSDCustomerMapper.php
@@ -65,6 +65,12 @@ final class GSDCustomerMapper extends DataMapperAbstract
         '_Partnernummer6'    => ['name' => '_Partnernummer6',    'type' => 'string',           'internal' => 'partner/6'],
     ];
 
+    /**
+     * Has one relation.
+     *
+     * @var array<string, array{mapper:string, external:string, by?:string, column?:string, conditional?:bool}>
+     * @since 1.0.0
+     */
     protected static array $ownsOne = [
         'addr' => [
             'mapper'     => GSDAddressMapper::class,
diff --git a/Interfaces/GSD/Model/GSDSupplier.php b/Interfaces/GSD/Model/GSDSupplier.php
index 8a9c387..e1745f3 100755
--- a/Interfaces/GSD/Model/GSDSupplier.php
+++ b/Interfaces/GSD/Model/GSDSupplier.php
@@ -26,7 +26,7 @@ class GSDSupplier
 {
     public int $id = 0;
 
-    public $createdBy = 0;
+    public int $createdBy = 0;
 
     public \DateTimeImmutable $createdAt;
 
diff --git a/Interfaces/GSD/Model/GSDSupplierMapper.php b/Interfaces/GSD/Model/GSDSupplierMapper.php
index 1c1085c..e413c23 100755
--- a/Interfaces/GSD/Model/GSDSupplierMapper.php
+++ b/Interfaces/GSD/Model/GSDSupplierMapper.php
@@ -45,6 +45,12 @@ final class GSDSupplierMapper extends DataMapperAbstract
         'AdressId'               => ['name' => 'AdressId',              'type' => 'int',   'internal' => 'addr'],
     ];
 
+    /**
+     * Has one relation.
+     *
+     * @var array<string, array{mapper:string, external:string, by?:string, column?:string, conditional?:bool}>
+     * @since 1.0.0
+     */
     protected static array $ownsOne = [
         'addr' => [
             'mapper'     => GSDAddressMapper::class,
diff --git a/Models/ExchangeLog.php b/Models/ExchangeLog.php
index aa0b7fe..8acbad0 100644
--- a/Models/ExchangeLog.php
+++ b/Models/ExchangeLog.php
@@ -61,7 +61,7 @@ class ExchangeLog implements \JsonSerializable, ArrayableInterface
     /**
      * Date type.
      *
-     * @var int
+     * @var \DateTimeImmutable
      * @since 1.0.0
      */
     private \DateTimeImmutable $createdAt;
@@ -167,7 +167,7 @@ class ExchangeLog implements \JsonSerializable, ArrayableInterface
     /**
      * Get created at.
      *
-     * @return DateTimeImmutable
+     * @return \DateTimeImmutable
      *
      * @since 1.0.0
      */
diff --git a/Models/ImporterAbstract.php b/Models/ImporterAbstract.php
index 5f95a65..7e078a9 100755
--- a/Models/ImporterAbstract.php
+++ b/Models/ImporterAbstract.php
@@ -14,7 +14,7 @@ declare(strict_types=1);
 
 namespace Modules\Exchange\Models;
 
-use phpOMS\DataStorage\Database\Connection\ConnectionInterface;
+use phpOMS\DataStorage\Database\Connection\ConnectionAbstract;
 use phpOMS\Message\RequestAbstract;
 
 /**
@@ -30,19 +30,19 @@ abstract class ImporterAbstract
     /**
      * Database connection.
      *
-     * @var ConnectionInterface
+     * @var ConnectionAbstract
      * @since 1.0.0
      */
-    protected $local = null;
+    protected ConnectionAbstract $local;
 
     /**
      * Constructor
      *
-     * @param ConnectionInterface $local Database connection
+     * @param ConnectionAbstract $local Database connection
      *
      * @since 1.0.0
      */
-    public function __construct(ConnectionInterface $local)
+    public function __construct(ConnectionAbstract $local)
     {
         $this->local = $local;
     }