diff --git a/Admin/Install/db.json b/Admin/Install/db.json
index f934ac2..142d2a6 100755
--- a/Admin/Install/db.json
+++ b/Admin/Install/db.json
@@ -40,5 +40,45 @@
                 "null": false
             }
         }
+    },
+    "exchange_log": {
+        "name": "exchange_log",
+        "fields": {
+            "exchange_log_id": {
+                "name": "exchange_log_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "exchange_log_message": {
+                "name": "exchange_log_message",
+                "type": "TEXT",
+                "null": false
+            },
+            "exchange_log_fields": {
+                "name": "exchange_log_fields",
+                "type": "TEXT",
+                "null": false
+            },
+            "exchange_log_type": {
+                "name": "exchange_log_type",
+                "type": "TINYINT",
+                "null": false
+            },
+            "exchange_log_time": {
+                "name": "exchange_log_time",
+                "type": "DATETIME",
+                "null": false
+            },
+            "exchange_log_exchange": {
+                "name": "exchange_log_exchange",
+                "type": "INT",
+                "default": null,
+                "null": true,
+                "foreignTable": "exchange",
+                "foreignKey": "exchange_id"
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/Interfaces/GSD/Model/ExchangeType.php b/Interfaces/GSD/Model/ExchangeType.php
new file mode 100755
index 0000000..5661953
--- /dev/null
+++ b/Interfaces/GSD/Model/ExchangeType.php
@@ -0,0 +1,47 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+
+declare(strict_types=1);
+
+namespace Modules\Exchange\Interfaces\GSD\Model;
+
+use phpOMS\Stdlib\Base\Enum;
+
+/**
+ * Exchange status enum.
+ *
+ * @package Modules\Exchange\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+abstract class ExchangeType extends Enum
+{
+    public const CUSTOMER = 1;
+
+    public const SUPPLIER = 2;
+
+    public const ARTICLE = 3;
+
+    public const BOOKING = 4;
+
+    public const ACCOUNT = 5;
+
+    public const ADDRESS = 6;
+
+    public const COSTCENTER = 7;
+
+    public const COSTOBJECT = 8;
+
+    public const INVOICE = 9;
+}
diff --git a/Interfaces/GSD/Model/GSDAddressMapper.php b/Interfaces/GSD/Model/GSDAddressMapper.php
index cbac02a..a5675c0 100755
--- a/Interfaces/GSD/Model/GSDAddressMapper.php
+++ b/Interfaces/GSD/Model/GSDAddressMapper.php
@@ -34,7 +34,7 @@ final class GSDAddressMapper extends DataMapperAbstract
      */
     protected static array $columns = [
         'AdressRowId'             => ['name' => 'AdressRowId',     'type' => 'int',      'internal' => 'id'],
-        'row_create_time'         => ['name' => 'row_create_time', 'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'row_create_time'         => ['name' => 'row_create_time', 'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user'         => ['name' => 'row_create_user', 'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
         'NAME1'                   => ['name' => 'NAME1',           'type' => 'string',   'internal' => 'name1'],
         'NAME2'                   => ['name' => 'NAME2',           'type' => 'string',   'internal' => 'name2'],
diff --git a/Interfaces/GSD/Model/GSDArticle.php b/Interfaces/GSD/Model/GSDArticle.php
index 95da32a..892a622 100755
--- a/Interfaces/GSD/Model/GSDArticle.php
+++ b/Interfaces/GSD/Model/GSDArticle.php
@@ -38,7 +38,7 @@ final class GSDArticle
      * @var \DateTime
      * @since 1.0.0
      */
-    private \DateTime $createdAt;
+    private \DateTimeImmutable $createdAt;
 
     /**
      * Article number.
@@ -135,7 +135,7 @@ final class GSDArticle
      */
     public function __construct()
     {
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
     }
 
     /**
diff --git a/Interfaces/GSD/Model/GSDArticleMapper.php b/Interfaces/GSD/Model/GSDArticleMapper.php
index 97a55d7..97b7704 100755
--- a/Interfaces/GSD/Model/GSDArticleMapper.php
+++ b/Interfaces/GSD/Model/GSDArticleMapper.php
@@ -34,7 +34,7 @@ final class GSDArticleMapper extends DataMapperAbstract
      */
     protected static array $columns = [
         'row_id'               => ['name' => 'row_id',               'type' => 'int',      'internal' => 'id'],
-        'row_create_time'      => ['name' => 'row_create_time',      'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'row_create_time'      => ['name' => 'row_create_time',      'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user'      => ['name' => 'row_create_user',      'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
         'Artikelnummer'        => ['name' => 'Artikelnummer',        'type' => 'string',   'internal' => 'number'],
         'Info'                 => ['name' => 'Info',        'type' => 'string',   'internal' => 'info'],
diff --git a/Interfaces/GSD/Model/GSDCostCenter.php b/Interfaces/GSD/Model/GSDCostCenter.php
index 12dd03d..dff7e4b 100755
--- a/Interfaces/GSD/Model/GSDCostCenter.php
+++ b/Interfaces/GSD/Model/GSDCostCenter.php
@@ -46,7 +46,7 @@ final class GSDCostCenter implements \JsonSerializable
      * @var \DateTime
      * @since 1.0.0
      */
-    protected \DateTime $createdAt;
+    protected \DateTimeImmutable $createdAt;
 
     /**
      * Description.
@@ -71,7 +71,7 @@ final class GSDCostCenter implements \JsonSerializable
      */
     public function __construct()
     {
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
     }
 
     /**
@@ -79,7 +79,7 @@ final class GSDCostCenter implements \JsonSerializable
      *
      * @since 1.0.0
      */
-    public function getCreatedAt() : \DateTime
+    public function getCreatedAt() : \DateTimeInterface
     {
         return $this->createdAt ?? new \DateTime();
     }
diff --git a/Interfaces/GSD/Model/GSDCostCenterMapper.php b/Interfaces/GSD/Model/GSDCostCenterMapper.php
index d8004db..4c41134 100755
--- a/Interfaces/GSD/Model/GSDCostCenterMapper.php
+++ b/Interfaces/GSD/Model/GSDCostCenterMapper.php
@@ -34,7 +34,7 @@ final class GSDCostCenterMapper extends DataMapperAbstract
      */
     protected static array $columns = [
         'ROW_ID'          => ['name' => 'ROW_ID',          'type' => 'int',      'internal' => 'id'],
-        'row_create_time' => ['name' => 'row_create_time', 'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'row_create_time' => ['name' => 'row_create_time', 'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user' => ['name' => 'row_create_user', 'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
         'KST'             => ['name' => 'KST',             'type' => 'string',   'internal' => 'costcenter'],
         'Bezeichnung'     => ['name' => 'Bezeichnung',     'type' => 'string',   'internal' => 'description'],
diff --git a/Interfaces/GSD/Model/GSDCostObject.php b/Interfaces/GSD/Model/GSDCostObject.php
index 7320b0a..3242489 100755
--- a/Interfaces/GSD/Model/GSDCostObject.php
+++ b/Interfaces/GSD/Model/GSDCostObject.php
@@ -46,7 +46,7 @@ final class GSDCostObject implements \JsonSerializable
      * @var \DateTime
      * @since 1.0.0
      */
-    protected \DateTime $createdAt;
+    protected \DateTimeImmutable $createdAt;
 
     /**
      * Description.
@@ -71,7 +71,7 @@ final class GSDCostObject implements \JsonSerializable
      */
     public function __construct()
     {
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
     }
 
     /**
@@ -79,7 +79,7 @@ final class GSDCostObject implements \JsonSerializable
      *
      * @since 1.0.0
      */
-    public function getCreatedAt() : \DateTime
+    public function getCreatedAt() : \DateTimeInterface
     {
         return $this->createdAt ?? new \DateTime();
     }
diff --git a/Interfaces/GSD/Model/GSDCostObjectMapper.php b/Interfaces/GSD/Model/GSDCostObjectMapper.php
index 6ebfcfa..8829e9c 100755
--- a/Interfaces/GSD/Model/GSDCostObjectMapper.php
+++ b/Interfaces/GSD/Model/GSDCostObjectMapper.php
@@ -34,7 +34,7 @@ final class GSDCostObjectMapper extends DataMapperAbstract
      */
     protected static array $columns = [
         'ROW_ID'          => ['name' => 'ROW_ID',          'type' => 'int',      'internal' => 'id'],
-        'row_create_time' => ['name' => 'row_create_time', 'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'row_create_time' => ['name' => 'row_create_time', 'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user' => ['name' => 'row_create_user', 'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
         'KTR'             => ['name' => 'KTR',             'type' => 'string',   'internal' => 'costobject'],
         'Bezeichnung'     => ['name' => 'Bezeichnung',     'type' => 'string',   'internal' => 'description'],
diff --git a/Interfaces/GSD/Model/GSDCustomer.php b/Interfaces/GSD/Model/GSDCustomer.php
index ea4bbb7..1426a10 100755
--- a/Interfaces/GSD/Model/GSDCustomer.php
+++ b/Interfaces/GSD/Model/GSDCustomer.php
@@ -46,7 +46,7 @@ final class GSDCustomer
      * @var \DateTime
      * @since 1.0.0
      */
-    protected \DateTime $createdAt;
+    protected \DateTimeImmutable $createdAt;
 
     /**
      * Customer number
@@ -138,7 +138,7 @@ final class GSDCustomer
     public function __construct()
     {
         $this->addr      = new GSDAddress();
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
     }
 
     /**
diff --git a/Interfaces/GSD/Model/GSDCustomerMapper.php b/Interfaces/GSD/Model/GSDCustomerMapper.php
index 3f8267c..a841b0c 100755
--- a/Interfaces/GSD/Model/GSDCustomerMapper.php
+++ b/Interfaces/GSD/Model/GSDCustomerMapper.php
@@ -34,7 +34,7 @@ final class GSDCustomerMapper extends DataMapperAbstract
      */
     protected static array $columns = [
         'row_id'            => ['name' => 'row_id',            'type' => 'int',      'internal' => 'id'],
-        'row_create_time'   => ['name' => 'row_create_time',   'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'row_create_time'   => ['name' => 'row_create_time',   'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user'   => ['name' => 'row_create_user',   'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
         'Kundennummer'      => ['name' => 'Kundennummer',      'type' => 'string',   'internal' => 'number'],
         'Info'              => ['name' => 'Info',              'type' => 'string',   'internal' => 'info'],
diff --git a/Interfaces/GSD/Model/GSDSupplier.php b/Interfaces/GSD/Model/GSDSupplier.php
index 0a74e45..96b8b1e 100755
--- a/Interfaces/GSD/Model/GSDSupplier.php
+++ b/Interfaces/GSD/Model/GSDSupplier.php
@@ -46,7 +46,7 @@ final class GSDSupplier
      * @var \DateTime
      * @since 1.0.0
      */
-    protected \DateTime $createdAt;
+    protected \DateTimeImmutable $createdAt;
 
     /**
      * Customer number
@@ -114,7 +114,7 @@ final class GSDSupplier
     public function __construct()
     {
         $this->addr      = new GSDAddress();
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
     }
 
     /**
diff --git a/Interfaces/GSD/Model/GSDSupplierMapper.php b/Interfaces/GSD/Model/GSDSupplierMapper.php
index 6a8cfb4..d989dce 100755
--- a/Interfaces/GSD/Model/GSDSupplierMapper.php
+++ b/Interfaces/GSD/Model/GSDSupplierMapper.php
@@ -34,7 +34,7 @@ final class GSDSupplierMapper extends DataMapperAbstract
      */
     protected static array $columns = [
         'row_id'                 => ['name' => 'row_id',            'type' => 'int',      'internal' => 'id'],
-        'row_create_time'        => ['name' => 'row_create_time',   'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'row_create_time'        => ['name' => 'row_create_time',   'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'row_create_user'        => ['name' => 'row_create_user',   'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
         'LieferantenNummer'      => ['name' => 'LieferantenNummer',      'type' => 'string',   'internal' => 'number'],
         'Info'                   => ['name' => 'Info',              'type' => 'string',   'internal' => 'info'],
diff --git a/Models/ExchangeLog.php b/Models/ExchangeLog.php
new file mode 100644
index 0000000..30d044f
--- /dev/null
+++ b/Models/ExchangeLog.php
@@ -0,0 +1,200 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Models;
+
+use phpOMS\Contract\ArrayableInterface;
+
+/**
+ * Exchange class.
+ *
+ * @package Modules\Exchange\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class ExchangeLog implements \JsonSerializable, ArrayableInterface
+{
+    /**
+     * Article ID.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $id = 0;
+
+    /**
+     * Message.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    private string $message = '';
+
+    /**
+     * Fields.
+     *
+     * @var array
+     * @since 1.0.0
+     */
+    private array $fields = [];
+
+    /**
+     * Log type.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    private int $type = ExchangeType::IMPORT;
+
+    /**
+     * Date type.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    private \DateTimeImmutable $createdAt;
+
+    /**
+     * Constructor.
+     *
+     * @since 1.0.0
+     */
+    public function __construct()
+    {
+        $this->createdAt = new \DateTimeImmutableImmutable('now');
+    }
+
+    /**
+     * Get type.
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public function getType() : int
+    {
+        return $this->type;
+    }
+
+    /**
+     * Set type.
+     *
+     * @param int $type Exchange type
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setType(int $type) : void
+    {
+        $this->type = $type;
+    }
+
+    /**
+     * Get id
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function getMessage() : string
+    {
+        return $this->message;
+    }
+
+    /**
+     * Set message
+     *
+     * @param string $message Log message
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setMessage(string $title) : void
+    {
+        $this->message = $message;
+    }
+
+    /**
+     * Get fields.
+     *
+     * @return array
+     *
+     * @since 1.0.0
+     */
+    public function getFields() : array
+    {
+        return $this->fields;
+    }
+
+    /**
+     * Set fields.
+     *
+     * @param array $fields Exchange fields
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setFields(array $fields) : void
+    {
+        $this->fields = $fields;
+    }
+
+    /**
+     * Get created at.
+     *
+     * @return array
+     *
+     * @since 1.0.0
+     */
+    public function getCreatedAt() : \DateTimeInterfaceInterface
+    {
+        return $this->createdAt;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray() : array
+    {
+        return [
+            'id'       => $this->id,
+            'message'  => $this->message,
+            'type'     => $this->type,
+            'fields'   => $this->fields,
+            'datetime' => $this->createdAt,
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+}
diff --git a/Models/ExchangeLogMapper.php b/Models/ExchangeLogMapper.php
new file mode 100644
index 0000000..0b1f269
--- /dev/null
+++ b/Models/ExchangeLogMapper.php
@@ -0,0 +1,66 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   Modules\Exchange\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Exchange\Models;
+
+use phpOMS\DataStorage\Database\DataMapperAbstract;
+
+/**
+ * Exchange log mapper class.
+ *
+ * @package Modules\Exchange\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class ExchangeLogMapper extends DataMapperAbstract
+{
+    /**
+     * Columns.
+     *
+     * @var array<string, array{name:string, type:string, internal:string, autocomplete?:bool, readonly?:bool, writeonly?:bool, annotations?:array}>
+     * @since 1.0.0
+     */
+    protected static array $columns = [
+        'exchange_log_id'    => ['name' => 'exchange_log_id',    'type' => 'int',    'internal' => 'id'],
+        'exchange_log_message' => ['name' => 'exchange_log_message', 'type' => 'string', 'internal' => 'message'],
+        'exchange_log_fields'  => ['name' => 'exchange_log_fields',  'type' => 'Json',    'internal' => 'fields'],
+        'exchange_log_type' => ['name' => 'exchange_log_type', 'type' => 'int',    'internal' => 'type'],
+        'exchange_log_time' => ['name' => 'exchange_log_time', 'type' => 'DateTimeImmutable',    'internal' => 'createdAt'],
+    ];
+
+    /**
+     * Model to use by the mapper.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $model = ExchangeLog::class;
+
+    /**
+     * Primary table.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $table = 'exchange_log';
+
+    /**
+     * Primary field name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $primaryField = 'exchange_log_id';
+}
\ No newline at end of file
diff --git a/Models/ExchangeType.php b/Models/ExchangeType.php
old mode 100755
new mode 100644
index 06fc2d8..a82c4f3
--- a/Models/ExchangeType.php
+++ b/Models/ExchangeType.php
@@ -27,21 +27,7 @@ use phpOMS\Stdlib\Base\Enum;
  */
 abstract class ExchangeType extends Enum
 {
-    public const CUSTOMER = 1;
+    public const IMPORT = 1;
 
-    public const SUPPLIER = 2;
-
-    public const ARTICLE = 3;
-
-    public const BOOKING = 4;
-
-    public const ACCOUNT = 5;
-
-    public const ADDRESS = 6;
-
-    public const COSTCENTER = 7;
-
-    public const COSTOBJECT = 8;
-
-    public const INVOICE = 9;
+    public const EXPORT = 2;
 }