diff --git a/Admin/Install/db.json b/Admin/Install/db.json
index 3c7b4d4..8d9c42e 100755
--- a/Admin/Install/db.json
+++ b/Admin/Install/db.json
@@ -31,8 +31,8 @@
                 "foreignTable": "calendar",
                 "foreignKey": "calendar_id"
             },
-            "projectmanagement_project_costs": {
-                "name": "projectmanagement_project_costs",
+            "projectmanagement_project_actualcosts": {
+                "name": "projectmanagement_project_actualcosts",
                 "type": "INT",
                 "null": false
             },
@@ -46,8 +46,8 @@
                 "type": "INT",
                 "null": false
             },
-            "projectmanagement_project_earnings": {
-                "name": "projectmanagement_project_earnings",
+            "projectmanagement_project_actualearnings": {
+                "name": "projectmanagement_project_actualearnings",
                 "type": "INT",
                 "null": false
             },
@@ -141,5 +141,197 @@
                 "foreignKey": "projectmanagement_project_id"
             }
         }
+    },
+    "projectmanagement_project_attr_type": {
+        "name": "projectmanagement_project_attr_type",
+        "fields": {
+            "projectmanagement_project_attr_type_id": {
+                "name": "projectmanagement_project_attr_type_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "projectmanagement_project_attr_type_name": {
+                "name": "projectmanagement_project_attr_type_name",
+                "type": "VARCHAR(255)",
+                "null": false
+            },
+            "projectmanagement_project_attr_type_fields": {
+                "name": "projectmanagement_project_attr_type_fields",
+                "type": "INT(11)",
+                "null": false
+            },
+            "projectmanagement_project_attr_type_custom": {
+                "name": "projectmanagement_project_attr_type_custom",
+                "type": "TINYINT(1)",
+                "null": false
+            },
+            "projectmanagement_project_attr_type_required": {
+                "description": "Every project must have this attribute type if set to true.",
+                "name": "projectmanagement_project_attr_type_required",
+                "type": "TINYINT(1)",
+                "null": false
+            },
+            "projectmanagement_project_attr_type_pattern": {
+                "description": "This is a regex validation pattern.",
+                "name": "projectmanagement_project_attr_type_pattern",
+                "type": "VARCHAR(255)",
+                "null": false
+            }
+        }
+    },
+    "projectmanagement_project_attr_type_l11n": {
+        "name": "projectmanagement_project_attr_type_l11n",
+        "fields": {
+            "projectmanagement_project_attr_type_l11n_id": {
+                "name": "projectmanagement_project_attr_type_l11n_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "projectmanagement_project_attr_type_l11n_title": {
+                "name": "projectmanagement_project_attr_type_l11n_title",
+                "type": "VARCHAR(255)",
+                "null": false
+            },
+            "projectmanagement_project_attr_type_l11n_type": {
+                "name": "projectmanagement_project_attr_type_l11n_type",
+                "type": "INT(11)",
+                "null": false,
+                "foreignTable": "projectmanagement_project_attr_type",
+                "foreignKey": "projectmanagement_project_attr_type_id"
+            },
+            "projectmanagement_project_attr_type_l11n_lang": {
+                "name": "projectmanagement_project_attr_type_l11n_lang",
+                "type": "VARCHAR(2)",
+                "null": false,
+                "foreignTable": "language",
+                "foreignKey": "language_639_1"
+            }
+        }
+    },
+    "projectmanagement_project_attr_value": {
+        "name": "projectmanagement_project_attr_value",
+        "fields": {
+            "projectmanagement_project_attr_value_id": {
+                "name": "projectmanagement_project_attr_value_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "projectmanagement_project_attr_value_default": {
+                "name": "projectmanagement_project_attr_value_default",
+                "type": "TINYINT(1)",
+                "null": false
+            },
+            "projectmanagement_project_attr_value_type": {
+                "name": "projectmanagement_project_attr_value_type",
+                "type": "INT(11)",
+                "null": false
+            },
+            "projectmanagement_project_attr_value_valueStr": {
+                "name": "projectmanagement_project_attr_value_valueStr",
+                "type": "VARCHAR(255)",
+                "null": true,
+                "default": null
+            },
+            "projectmanagement_project_attr_value_valueInt": {
+                "name": "projectmanagement_project_attr_value_valueInt",
+                "type": "INT(11)",
+                "null": true,
+                "default": null
+            },
+            "projectmanagement_project_attr_value_valueDec": {
+                "name": "projectmanagement_project_attr_value_valueDec",
+                "type": "DECIMAL(19,5)",
+                "null": true,
+                "default": null
+            },
+            "projectmanagement_project_attr_value_valueDat": {
+                "name": "projectmanagement_project_attr_value_valueDat",
+                "type": "DATETIME",
+                "null": true,
+                "default": null
+            },
+            "projectmanagement_project_attr_value_lang": {
+                "name": "projectmanagement_project_attr_value_lang",
+                "type": "VARCHAR(2)",
+                "null": true,
+                "default": null,
+                "foreignTable": "language",
+                "foreignKey": "language_639_1"
+            },
+            "projectmanagement_project_attr_value_country": {
+                "name": "projectmanagement_project_attr_value_country",
+                "type": "VARCHAR(2)",
+                "null": true,
+                "default": null,
+                "foreignTable": "country",
+                "foreignKey": "country_code2"
+            }
+        }
+    },
+    "projectmanagement_project_attr_default": {
+        "name": "projectmanagement_project_attr_default",
+        "fields": {
+            "projectmanagement_project_attr_default_id": {
+                "name": "projectmanagement_project_attr_default_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "projectmanagement_project_attr_default_type": {
+                "name": "projectmanagement_project_attr_default_type",
+                "type": "INT(11)",
+                "null": false,
+                "foreignTable": "projectmanagement_project_attr_type",
+                "foreignKey": "projectmanagement_project_attr_type_id"
+            },
+            "projectmanagement_project_attr_default_value": {
+                "name": "projectmanagement_project_attr_default_value",
+                "type": "INT(11)",
+                "null": false,
+                "foreignTable": "projectmanagement_project_attr_value",
+                "foreignKey": "projectmanagement_project_attr_value_id"
+            }
+        }
+    },
+    "projectmanagement_project_attr": {
+        "name": "projectmanagement_project_attr",
+        "fields": {
+            "projectmanagement_project_attr_id": {
+                "name": "projectmanagement_project_attr_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "projectmanagement_project_attr_project": {
+                "name": "projectmanagement_project_attr_project",
+                "type": "INT(11)",
+                "null": false,
+                "foreignTable": "projectmanagement_project",
+                "foreignKey": "projectmanagement_project_id"
+            },
+            "projectmanagement_project_attr_type": {
+                "name": "projectmanagement_project_attr_type",
+                "type": "INT(11)",
+                "null": false,
+                "foreignTable": "projectmanagement_project_attr_type",
+                "foreignKey": "projectmanagement_project_attr_type_id"
+            },
+            "projectmanagement_project_attr_value": {
+                "name": "projectmanagement_project_attr_value",
+                "type": "INT(11)",
+                "null": true,
+                "default": null,
+                "foreignTable": "projectmanagement_project_attr_value",
+                "foreignKey": "projectmanagement_project_attr_value_id"
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/Models/AttributeValueType.php b/Models/AttributeValueType.php
new file mode 100644
index 0000000..eae62dc
--- /dev/null
+++ b/Models/AttributeValueType.php
@@ -0,0 +1,36 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\Stdlib\Base\Enum;
+
+/**
+ * Attribute value type enum.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+abstract class AttributeValueType extends Enum
+{
+    public const _INT = 1;
+
+    public const _STRING = 2;
+
+    public const _FLOAT = 3;
+
+    public const _DATETIME = 4;
+}
diff --git a/Models/NullProjectAttribute.php b/Models/NullProjectAttribute.php
new file mode 100644
index 0000000..0366692
--- /dev/null
+++ b/Models/NullProjectAttribute.php
@@ -0,0 +1,39 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+/**
+ * Null model
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class NullProjectAttribute extends ProjectAttribute
+{
+    /**
+     * Constructor
+     *
+     * @param int $id Model id
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $id = 0)
+    {
+        parent::__construct();
+        $this->id = $id;
+    }
+}
diff --git a/Models/NullProjectAttributeType.php b/Models/NullProjectAttributeType.php
new file mode 100644
index 0000000..9aaaa6b
--- /dev/null
+++ b/Models/NullProjectAttributeType.php
@@ -0,0 +1,38 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+/**
+ * Null model
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class NullProjectAttributeType extends ProjectAttributeType
+{
+    /**
+     * Constructor
+     *
+     * @param int $id Model id
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $id = 0)
+    {
+        $this->id = $id;
+    }
+}
diff --git a/Models/NullProjectAttributeTypeL11n.php b/Models/NullProjectAttributeTypeL11n.php
new file mode 100644
index 0000000..2755d39
--- /dev/null
+++ b/Models/NullProjectAttributeTypeL11n.php
@@ -0,0 +1,38 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+/**
+ * Null model
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class NullProjectAttributeTypeL11n extends ProjectAttributeTypeL11n
+{
+    /**
+     * Constructor
+     *
+     * @param int $id Model id
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $id = 0)
+    {
+        $this->id = $id;
+    }
+}
diff --git a/Models/NullProjectAttributeValue.php b/Models/NullProjectAttributeValue.php
new file mode 100644
index 0000000..dfb83b0
--- /dev/null
+++ b/Models/NullProjectAttributeValue.php
@@ -0,0 +1,38 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+/**
+ * Null model
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class NullProjectAttributeValue extends ProjectAttributeValue
+{
+    /**
+     * Constructor
+     *
+     * @param int $id Model id
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $id = 0)
+    {
+        $this->id = $id;
+    }
+}
diff --git a/Models/Project.php b/Models/Project.php
index 975c721..1e2cc55 100755
--- a/Models/Project.php
+++ b/Models/Project.php
@@ -95,14 +95,6 @@ class Project
      */
     public Calendar $calendar;
 
-    /**
-     * Current total costs.
-     *
-     * @var Money
-     * @since 1.0.0
-     */
-    public Money $costs;
-
     /**
      * Budget costs.
      *
@@ -119,13 +111,21 @@ class Project
      */
     public Money $budgetEarnings;
 
+    /**
+     * Current total costs.
+     *
+     * @var Money
+     * @since 1.0.0
+     */
+    public Money $actualCosts;
+
     /**
      * Current total earnings.
      *
      * @var Money
      * @since 1.0.0
      */
-    public Money $earnings;
+    public Money $actualEarnings;
 
     /**
      * Progress percentage.
@@ -175,6 +175,14 @@ class Project
      */
     private $tasks = [];
 
+    /**
+     * Attributes.
+     *
+     * @var int[]|ProjectAttribute[]
+     * @since 1.0.0
+     */
+    private array $attributes = [];
+
     /**
      * Constructor.
      *
@@ -194,10 +202,10 @@ class Project
 
         $this->calendar = new Calendar();
 
-        $this->costs          = new Money();
+        $this->actualCosts    = new Money();
+        $this->actualEarnings = new Money();
         $this->budgetCosts    = new Money();
         $this->budgetEarnings = new Money();
-        $this->earnings       = new Money();
 
         $this->setName($name);
     }
@@ -373,6 +381,32 @@ class Project
         $this->calendar->name = $name;
     }
 
+    /**
+     * Add attribute to item
+     *
+     * @param ProjectAttribute $attribute Note
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function addAttribute(ProjectAttribute $attribute) : void
+    {
+        $this->attributes[] = $attribute;
+    }
+
+    /**
+     * Get attributes
+     *
+     * @return int[]|ProjectAttribute[]
+     *
+     * @since 1.0.0
+     */
+    public function getAttributes() : array
+    {
+        return $this->attributes;
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -385,10 +419,10 @@ class Project
             'name'                 => $this->name,
             'description'          => $this->description,
             'calendar'             => $this->calendar,
-            'costs'                => $this->costs,
             'budgetCosts'          => $this->budgetCosts,
             'budgetEarnings'       => $this->budgetEarnings,
-            'earnings'             => $this->earnings,
+            'actualCosts'          => $this->actualCosts,
+            'actualEarnings'       => $this->actualEarnings,
             'tasks'                => $this->tasks,
             'media'                => $this->media,
             'progress'             => $this->progress,
diff --git a/Models/ProjectAttribute.php b/Models/ProjectAttribute.php
new file mode 100644
index 0000000..8a8b431
--- /dev/null
+++ b/Models/ProjectAttribute.php
@@ -0,0 +1,104 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\Contract\ArrayableInterface;
+
+/**
+ * Project class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class ProjectAttribute implements \JsonSerializable, ArrayableInterface
+{
+    /**
+     * Id.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $id = 0;
+
+    /**
+     * Project this attribute belongs to
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    public int $project = 0;
+
+    /**
+     * Attribute type the attribute belongs to
+     *
+     * @var ProjectAttributeType
+     * @since 1.0.0
+     */
+    public ProjectAttributeType $type;
+
+    /**
+     * Attribute value the attribute belongs to
+     *
+     * @var ProjectAttributeValue
+     * @since 1.0.0
+     */
+    public ProjectAttributeValue $value;
+
+    /**
+     * Constructor.
+     *
+     * @since 1.0.0
+     */
+    public function __construct()
+    {
+        $this->type  = new NullProjectAttributeType();
+        $this->value = new NullProjectAttributeValue();
+    }
+
+    /**
+     * Get id
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray() : array
+    {
+        return [
+            'id'    => $this->id,
+            'item'  => $this->item,
+            'type'  => $this->type,
+            'value' => $this->value,
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+}
diff --git a/Models/ProjectAttributeMapper.php b/Models/ProjectAttributeMapper.php
new file mode 100644
index 0000000..23b57df
--- /dev/null
+++ b/Models/ProjectAttributeMapper.php
@@ -0,0 +1,74 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\DataStorage\Database\DataMapperAbstract;
+
+/**
+ * Project mapper class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class ProjectAttributeMapper 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 = [
+        'projectmanagement_project_attr_id'    => ['name' => 'projectmanagement_project_attr_id',    'type' => 'int', 'internal' => 'id'],
+        'projectmanagement_project_attr_project'  => ['name' => 'projectmanagement_project_attr_project',  'type' => 'int', 'internal' => 'project'],
+        'projectmanagement_project_attr_type'  => ['name' => 'projectmanagement_project_attr_type',  'type' => 'int', 'internal' => 'type'],
+        'projectmanagement_project_attr_value' => ['name' => 'projectmanagement_project_attr_value', 'type' => 'int', 'internal' => 'value'],
+    ];
+
+    /**
+     * 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 = [
+        'type' => [
+            'mapper'            => ProjectAttributeTypeMapper::class,
+            'external'          => 'projectmanagement_project_attr_type',
+        ],
+        'value' => [
+            'mapper'            => ProjectAttributeValueMapper::class,
+            'external'          => 'projectmanagement_project_attr_value',
+        ],
+    ];
+
+    /**
+     * Primary table.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $table = 'projectmanagement_project_attr';
+
+    /**
+     * Primary field name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $primaryField = 'projectmanagement_project_attr_id';
+}
diff --git a/Models/ProjectAttributeType.php b/Models/ProjectAttributeType.php
new file mode 100644
index 0000000..7613e31
--- /dev/null
+++ b/Models/ProjectAttributeType.php
@@ -0,0 +1,172 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\Contract\ArrayableInterface;
+use phpOMS\Localization\ISO639x1Enum;
+
+/**
+ * Project Attribute Type class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class ProjectAttributeType implements \JsonSerializable, ArrayableInterface
+{
+    /**
+     * Id
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $id = 0;
+
+    /**
+     * Name/string identifier by which it can be found/categorized
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    public string $name = ''; // @todo: currently not filled, should be used as identifier or if not required removed (at the moment it seems like it is useless?!)
+
+    /**
+     * Which field data type is required (string, int, ...) in the value
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $fields = 0;
+
+    /**
+     * Is a custom value allowed (e.g. custom string)
+     *
+     * @var bool
+     * @since 1.0.0
+     */
+    public bool $custom = false;
+
+    public string $validationPattern = '';
+
+    public bool $isRequired = false;
+
+    /**
+     * Localization
+     *
+     * @var ProjectAttributeTypeL11n
+     */
+    private string | ProjectAttributeTypeL11n $l11n;
+
+    /**
+     * Possible default attribute values
+     *
+     * @var array
+     */
+    private array $defaults = [];
+
+    /**
+     * Constructor.
+     *
+     * @param string $name Name/identifier of the attribute type
+     *
+     * @since 1.0.0
+     */
+    public function __construct(string $name = '')
+    {
+        $this->setL11n($name);
+    }
+
+    /**
+     * Get id
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set l11n
+     *
+     * @param string|ProjectAttributeTypeL11n $l11n Tag article l11n
+     * @param string                       $lang Language
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setL11n(string | ProjectAttributeTypeL11n $l11n, string $lang = ISO639x1Enum::_EN) : void
+    {
+        if ($l11n instanceof ProjectAttributeTypeL11n) {
+            $this->l11n = $l11n;
+        } elseif (isset($this->l11n) && $this->l11n instanceof ProjectAttributeTypeL11n) {
+            $this->l11n->title = $l11n;
+        } else {
+            $this->l11n        = new ProjectAttributeTypeL11n();
+            $this->l11n->title = $l11n;
+            $this->l11n->setLanguage($lang);
+        }
+    }
+
+    /**
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function getL11n() : string
+    {
+        return $this->l11n instanceof ProjectAttributeTypeL11n ? $this->l11n->title : $this->l11n;
+    }
+
+    /**
+     * Set fields
+     *
+     * @param int $fields Fields
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setFields(int $fields) : void
+    {
+        $this->fields = $fields;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray() : array
+    {
+        return [
+            'id'                => $this->id,
+            'name'              => $this->name,
+            'validationPattern' => $this->validationPattern,
+            'custom'            => $this->custom,
+            'isRequired'        => $this->isRequired,
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+}
diff --git a/Models/ProjectAttributeTypeL11n.php b/Models/ProjectAttributeTypeL11n.php
new file mode 100644
index 0000000..74787bd
--- /dev/null
+++ b/Models/ProjectAttributeTypeL11n.php
@@ -0,0 +1,136 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\Contract\ArrayableInterface;
+use phpOMS\Localization\ISO639x1Enum;
+
+/**
+ * Project class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class ProjectAttributeTypeL11n implements \JsonSerializable, ArrayableInterface
+{
+    /**
+     * ID.
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $id = 0;
+
+    /**
+     * Project ID.
+     *
+     * @var int|ProjectAttributeType
+     * @since 1.0.0
+     */
+    public int | ProjectAttributeType $type = 0;
+
+    /**
+     * Language.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected string $language = ISO639x1Enum::_EN;
+
+    /**
+     * Title.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    public string $title = '';
+
+    /**
+     * Constructor.
+     *
+     * @param int|ProjectAttributeType $type     Attribute type
+     * @param string                $title    Localized title
+     * @param string                $language Language
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int | ProjectAttributeType $type = 0, string $title = '', string $language = ISO639x1Enum::_EN)
+    {
+        $this->type     = $type;
+        $this->title    = $title;
+        $this->language = $language;
+    }
+
+    /**
+     * Get id
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * Get language
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function getLanguage() : string
+    {
+        return $this->language;
+    }
+
+    /**
+     * Set language
+     *
+     * @param string $language Language
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setLanguage(string $language) : void
+    {
+        $this->language = $language;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray() : array
+    {
+        return [
+            'id'       => $this->id,
+            'title'    => $this->title,
+            'type'     => $this->type,
+            'language' => $this->language,
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+}
diff --git a/Models/ProjectAttributeTypeL11nMapper.php b/Models/ProjectAttributeTypeL11nMapper.php
new file mode 100644
index 0000000..39aba30
--- /dev/null
+++ b/Models/ProjectAttributeTypeL11nMapper.php
@@ -0,0 +1,57 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\DataStorage\Database\DataMapperAbstract;
+
+/**
+ * Project mapper class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class ProjectAttributeTypeL11nMapper 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 = [
+        'projectmanagement_project_attr_type_l11n_id'        => ['name' => 'projectmanagement_project_attr_type_l11n_id',       'type' => 'int',    'internal' => 'id'],
+        'projectmanagement_project_attr_type_l11n_title'     => ['name' => 'projectmanagement_project_attr_type_l11n_title',    'type' => 'string', 'internal' => 'title', 'autocomplete' => true],
+        'projectmanagement_project_attr_type_l11n_type'      => ['name' => 'projectmanagement_project_attr_type_l11n_type',      'type' => 'int',    'internal' => 'type'],
+        'projectmanagement_project_attr_type_l11n_lang'      => ['name' => 'projectmanagement_project_attr_type_l11n_lang', 'type' => 'string', 'internal' => 'language'],
+    ];
+
+    /**
+     * Primary table.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $table = 'projectmanagement_project_attr_type_l11n';
+
+    /**
+     * Primary field name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $primaryField = 'projectmanagement_project_attr_type_l11n_id';
+}
diff --git a/Models/ProjectAttributeTypeMapper.php b/Models/ProjectAttributeTypeMapper.php
new file mode 100644
index 0000000..8ce2688
--- /dev/null
+++ b/Models/ProjectAttributeTypeMapper.php
@@ -0,0 +1,83 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\DataStorage\Database\DataMapperAbstract;
+
+/**
+ * Project mapper class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class ProjectAttributeTypeMapper 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 = [
+        'projectmanagement_project_attr_type_id'       => ['name' => 'projectmanagement_project_attr_type_id',     'type' => 'int',    'internal' => 'id'],
+        'projectmanagement_project_attr_type_name'     => ['name' => 'projectmanagement_project_attr_type_name',   'type' => 'string', 'internal' => 'name', 'autocomplete' => true],
+        'projectmanagement_project_attr_type_fields'   => ['name' => 'projectmanagement_project_attr_type_fields', 'type' => 'int',    'internal' => 'fields'],
+        'projectmanagement_project_attr_type_custom'   => ['name' => 'projectmanagement_project_attr_type_custom', 'type' => 'bool', 'internal' => 'custom'],
+        'projectmanagement_project_attr_type_pattern'  => ['name' => 'projectmanagement_project_attr_type_pattern', 'type' => 'string', 'internal' => 'validationPattern'],
+        'projectmanagement_project_attr_type_required' => ['name' => 'projectmanagement_project_attr_type_required', 'type' => 'bool', 'internal' => 'isRequired'],
+    ];
+
+    /**
+     * Has many relation.
+     *
+     * @var array<string, array{mapper:string, table:string, self?:?string, external?:?string, column?:string}>
+     * @since 1.0.0
+     */
+    protected static array $hasMany = [
+        'l11n' => [
+            'mapper'            => ProjectAttributeTypeL11nMapper::class,
+            'table'             => 'projectmanagement_project_attr_type_l11n',
+            'self'              => 'projectmanagement_project_attr_type_l11n_type',
+            'column'            => 'title',
+            'conditional'       => true,
+            'external'          => null,
+        ],
+        'defaults' => [
+            'mapper'            => ProjectAttributeValueMapper::class,
+            'table'             => 'projectmanagement_project_attr_default',
+            'self'              => 'projectmanagement_project_attr_default_type',
+            'external'          => 'projectmanagement_project_attr_default_value',
+            'conditional'       => false,
+        ],
+    ];
+
+    /**
+     * Primary table.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $table = 'projectmanagement_project_attr_type';
+
+    /**
+     * Primary field name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $primaryField = 'projectmanagement_project_attr_type_id';
+}
diff --git a/Models/ProjectAttributeValue.php b/Models/ProjectAttributeValue.php
new file mode 100644
index 0000000..e2b011a
--- /dev/null
+++ b/Models/ProjectAttributeValue.php
@@ -0,0 +1,255 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\Contract\ArrayableInterface;
+use phpOMS\Localization\ISO3166TwoEnum;
+use phpOMS\Localization\ISO639x1Enum;
+
+/**
+ * Project attribute value class.
+ *
+ * The relation with the type/item is defined in the ProjectAttribute class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+class ProjectAttributeValue implements \JsonSerializable, ArrayableInterface
+{
+    /**
+     * Id
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    protected int $id = 0;
+
+    /**
+     * Type of the attribute
+     *
+     * @var int
+     * @since 1.0.0
+     */
+    public int $type = 0;
+
+    /**
+     * Int value
+     *
+     * @var null|int
+     * @since 1.0.0
+     */
+    public ?int $valueInt = null;
+
+    /**
+     * String value
+     *
+     * @var null|string
+     * @since 1.0.0
+     */
+    public ?string $valueStr = null;
+
+    /**
+     * Decimal value
+     *
+     * @var null|float
+     * @since 1.0.0
+     */
+    public ?float $valueDec = null;
+
+    /**
+     * DateTime value
+     *
+     * @var null|\DateTimeInterface
+     * @since 1.0.0
+     */
+    public ?\DateTimeInterface $valueDat = null;
+
+    /**
+     * Is a default value which can be selected
+     *
+     * @var bool
+     * @since 1.0.0
+     */
+    public bool $isDefault = false;
+
+    /**
+     * Language
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected string $language = ISO639x1Enum::_EN;
+
+    /**
+     * Country
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected string $country = ISO3166TwoEnum::_USA;
+
+    /**
+     * Constructor.
+     *
+     * @param int    $type     Type
+     * @param mixed  $value    Value
+     * @param string $language Language
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $type = 0, $value = '', string $language = ISO639x1Enum::_EN)
+    {
+        $this->type     = $type;
+        $this->language = $language;
+
+        $this->setValue($value);
+    }
+
+    /**
+     * Get id
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    public function getId() : int
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set value
+     *
+     * @param int|string|float|\DateTimeInterface $value Value
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setValue(mixed $value) : void
+    {
+        if (\is_string($value)) {
+            $this->valueStr = $value;
+        } elseif (\is_int($value)) {
+            $this->valueInt = $value;
+        } elseif (\is_float($value)) {
+            $this->valueDec = $value;
+        } elseif ($value instanceof \DateTimeInterface) {
+            $this->valueDat = $value;
+        }
+    }
+
+    /**
+     * Get value
+     *
+     * @return null|int|string|float|\DateTimeInterface
+     *
+     * @since 1.0.0
+     */
+    public function getValue() : mixed
+    {
+        if (!empty($this->valueStr)) {
+            return $this->valueStr;
+        } elseif (!empty($this->valueInt)) {
+            return $this->valueInt;
+        } elseif (!empty($this->valueDec)) {
+            return $this->valueDec;
+        } elseif ($this->valueDat instanceof \DateTimeInterface) {
+            return $this->valueDat;
+        }
+
+        return null;
+    }
+
+    /**
+     * Set language
+     *
+     * @param string $language Language
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setLanguage(string $language) : void
+    {
+        $this->language = $language;
+    }
+
+    /**
+     * Get language
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function getLanguage() : string
+    {
+        return $this->language;
+    }
+
+    /**
+     * Set country
+     *
+     * @param string $country Country
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function setCountry(string $country) : void
+    {
+        $this->country = $country;
+    }
+
+    /**
+     * Get country
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function getCountry() : string
+    {
+        return $this->country;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray() : array
+    {
+        return [
+            'id'        => $this->id,
+            'type'      => $this->type,
+            'valueInt'  => $this->valueInt,
+            'valueStr'  => $this->valueStr,
+            'valueDec'  => $this->valueDec,
+            'valueDat'  => $this->valueDat,
+            'isDefault' => $this->isDefault,
+            'language'  => $this->language,
+            'country'   => $this->country,
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
+}
diff --git a/Models/ProjectAttributeValueMapper.php b/Models/ProjectAttributeValueMapper.php
new file mode 100644
index 0000000..c23669a
--- /dev/null
+++ b/Models/ProjectAttributeValueMapper.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   Modules\ProjectManagement\Models
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https:   //orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\ProjectManagement\Models;
+
+use phpOMS\DataStorage\Database\DataMapperAbstract;
+
+/**
+ * Project mapper class.
+ *
+ * @package Modules\ProjectManagement\Models
+ * @license OMS License 1.0
+ * @link    https:   //orange-management.org
+ * @since   1.0.0
+ */
+final class ProjectAttributeValueMapper 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 = [
+        'projectmanagement_project_attr_value_id'       => ['name' => 'projectmanagement_project_attr_value_id',       'type' => 'int',    'internal' => 'id'],
+        'projectmanagement_project_attr_value_default'  => ['name' => 'projectmanagement_project_attr_value_default',  'type' => 'bool', 'internal' => 'isDefault'],
+        'projectmanagement_project_attr_value_type'     => ['name' => 'projectmanagement_project_attr_value_type',     'type' => 'int',    'internal' => 'type'],
+        'projectmanagement_project_attr_value_valueStr' => ['name' => 'projectmanagement_project_attr_value_valueStr', 'type' => 'string', 'internal' => 'valueStr'],
+        'projectmanagement_project_attr_value_valueInt' => ['name' => 'projectmanagement_project_attr_value_valueInt', 'type' => 'int', 'internal' => 'valueInt'],
+        'projectmanagement_project_attr_value_valueDec' => ['name' => 'projectmanagement_project_attr_value_valueDec', 'type' => 'float', 'internal' => 'valueDec'],
+        'projectmanagement_project_attr_value_valueDat' => ['name' => 'projectmanagement_project_attr_value_valueDat', 'type' => 'DateTime', 'internal' => 'valueDat'],
+        'projectmanagement_project_attr_value_lang'     => ['name' => 'projectmanagement_project_attr_value_lang',     'type' => 'string', 'internal' => 'language'],
+        'projectmanagement_project_attr_value_country'  => ['name' => 'projectmanagement_project_attr_value_country',  'type' => 'string', 'internal' => 'country'],
+    ];
+
+    /**
+     * Primary table.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $table = 'projectmanagement_project_attr_value';
+
+    /**
+     * Primary field name.
+     *
+     * @var string
+     * @since 1.0.0
+     */
+    protected static string $primaryField = 'projectmanagement_project_attr_value_id';
+}
diff --git a/Models/ProjectMapper.php b/Models/ProjectMapper.php
index 96c7dfd..c2b6879 100755
--- a/Models/ProjectMapper.php
+++ b/Models/ProjectMapper.php
@@ -42,10 +42,10 @@ final class ProjectMapper extends DataMapperAbstract
         'projectmanagement_project_description'     => ['name' => 'projectmanagement_project_description',     'type' => 'string',       'internal' => 'description'],
         'projectmanagement_project_description_raw' => ['name' => 'projectmanagement_project_description_raw', 'type' => 'string',       'internal' => 'descriptionRaw'],
         'projectmanagement_project_calendar'        => ['name' => 'projectmanagement_project_calendar',        'type' => 'int',          'internal' => 'calendar'],
-        'projectmanagement_project_costs'           => ['name' => 'projectmanagement_project_costs',           'type' => 'Serializable', 'internal' => 'costs'],
         'projectmanagement_project_budgetcosts'     => ['name' => 'projectmanagement_project_budgetcosts',     'type' => 'Serializable', 'internal' => 'budgetCosts'],
         'projectmanagement_project_budgetearnings'  => ['name' => 'projectmanagement_project_budgetearnings',  'type' => 'Serializable', 'internal' => 'budgetEarnings'],
-        'projectmanagement_project_earnings'        => ['name' => 'projectmanagement_project_earnings',        'type' => 'Serializable', 'internal' => 'earnings'],
+        'projectmanagement_project_actualearnings'        => ['name' => 'projectmanagement_project_actualearnings',        'type' => 'Serializable', 'internal' => 'actualEarnings'],
+        'projectmanagement_project_actualcosts'        => ['name' => 'projectmanagement_project_actualcosts',        'type' => 'Serializable', 'internal' => 'actualCosts'],
         'projectmanagement_project_start'           => ['name' => 'projectmanagement_project_start',           'type' => 'DateTime',     'internal' => 'start'],
         'projectmanagement_project_end'             => ['name' => 'projectmanagement_project_end',             'type' => 'DateTime',     'internal' => 'end'],
         'projectmanagement_project_endestimated'    => ['name' => 'projectmanagement_project_endestimated',    'type' => 'DateTime',     'internal' => 'endEstimated'],
@@ -74,6 +74,13 @@ final class ProjectMapper extends DataMapperAbstract
             'external' => 'projectmanagement_project_media_dst',
             'self'     => 'projectmanagement_project_media_src',
         ],
+        'attributes' => [
+            'mapper'      => ProjectAttributeMapper::class,
+            'table'       => 'projectmanagement_project_attr',
+            'self'        => 'projectmanagement_project_attr_project',
+            'conditional' => true,
+            'external'    => null,
+        ],
     ];
 
     /**
diff --git a/tests/Models/ProjectMapperTest.php b/tests/Models/ProjectMapperTest.php
index 664adad..a960bc7 100755
--- a/tests/Models/ProjectMapperTest.php
+++ b/tests/Models/ProjectMapperTest.php
@@ -44,10 +44,10 @@ final class ProjectMapperTest extends \PHPUnit\Framework\TestCase
         $money = new Money();
         $money->setString('1.23');
 
-        $project->costs          = $money;
         $project->budgetCosts    = $money;
         $project->budgetEarnings = $money;
-        $project->earnings       = $money;
+        $project->actualCosts       = $money;
+        $project->actualEarnings          = $money;
 
         $task        = new Task();
         $task->title = 'ProjectTask 1';
@@ -80,10 +80,10 @@ final class ProjectMapperTest extends \PHPUnit\Framework\TestCase
 
         self::assertEquals($project->getName(), $projectR->getName());
         self::assertEquals($project->description, $projectR->description);
-        self::assertEquals($project->costs->getAmount(), $projectR->costs->getAmount());
         self::assertEquals($project->budgetEarnings->getAmount(), $projectR->budgetEarnings->getAmount());
         self::assertEquals($project->budgetCosts->getAmount(), $projectR->budgetCosts->getAmount());
-        self::assertEquals($project->earnings->getAmount(), $projectR->earnings->getAmount());
+        self::assertEquals($project->actualCosts->getAmount(), $projectR->actualCosts->getAmount());
+        self::assertEquals($project->actualEarnings->getAmount(), $projectR->actualEarnings->getAmount());
         self::assertEquals($project->createdAt->format('Y-m-d'), $projectR->createdAt->format('Y-m-d'));
         self::assertEquals($project->start->format('Y-m-d'), $projectR->start->format('Y-m-d'));
         self::assertEquals($project->end->format('Y-m-d'), $projectR->end->format('Y-m-d'));
diff --git a/tests/Models/ProjectTest.php b/tests/Models/ProjectTest.php
index b6cf729..4f858af 100755
--- a/tests/Models/ProjectTest.php
+++ b/tests/Models/ProjectTest.php
@@ -50,10 +50,10 @@ final class ProjectTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(0, $this->project->createdBy->getId());
         self::assertEquals('', $this->project->getName());
         self::assertEquals('', $this->project->description);
-        self::assertEquals(0, $this->project->costs->getInt());
         self::assertEquals(0, $this->project->budgetCosts->getInt());
         self::assertEquals(0, $this->project->budgetEarnings->getInt());
-        self::assertEquals(0, $this->project->earnings->getInt());
+        self::assertEquals(0, $this->project->actualCosts->getInt());
+        self::assertEquals(0, $this->project->actualEarnings->getInt());
         self::assertEquals(0, $this->project->progress);
         self::assertEquals([], $this->project->getMedia());
         self::assertEquals(ProgressType::MANUAL, $this->project->getProgressType());
@@ -179,10 +179,10 @@ final class ProjectTest extends \PHPUnit\Framework\TestCase
                 'end'                  => $this->project->end,
                 'name'                 => 'Name',
                 'description'          => 'Description',
-                'costs'                => new Money(),
                 'budgetCosts'          => new Money(),
                 'budgetEarnings'       => new Money(),
-                'earnings'             => new Money(),
+                'actualCosts'             => new Money(),
+                'actualEarnings'             => new Money(),
                 'tasks'                => [],
                 'media'                => [],
                 'progress'             => 10,