diff --git a/config/Migrations/20201110234846_AddCollectionColumn.php b/config/Migrations/20201110234846_AddCollectionColumn.php
new file mode 100644
index 0000000..2edca26
--- /dev/null
+++ b/config/Migrations/20201110234846_AddCollectionColumn.php
@@ -0,0 +1,21 @@
+<?php
+declare(strict_types=1);
+
+use Migrations\AbstractMigration;
+
+class AddCollectionColumn extends AbstractMigration
+{
+    /**
+     * Change Method.
+     *
+     * More information on this method is available here:
+     * https://book.cakephp.org/phinx/0/en/migrations.html#the-change-method
+     * @return void
+     */
+    public function change()
+    {
+        $this->table('file_storage')
+            ->addColumn('collection', 'string', ['length' => 128, 'null' => true, 'default' => null])
+            ->update();
+    }
+}
diff --git a/phpcs.xml b/phpcs.xml
index 260755e..61f0a9a 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -10,12 +10,12 @@
 
     <rule ref="SlevomatCodingStandard.TypeHints.DeclareStrictTypes">
         <properties>
-            <property name="newlinesCountBetweenOpenTagAndDeclare" value="2" />
+            <property name="newlinesCountBetweenOpenTagAndDeclare" value="2"/>
         </properties>
     </rule>
 
     <rule ref="Spryker">
-        <exclude name="Spryker.Formatting.MethodSignatureParametersLineBreakMethod" />
+        <exclude name="Spryker.Formatting.MethodSignatureParametersLineBreakMethod"/>
     </rule>
 
 </ruleset>
diff --git a/phpstan.neon b/phpstan.neon
index bd7887a..02e6eb7 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,5 +1,5 @@
 parameters:
-    level: 7
+    level: 8
     checkMissingIterableValueType: false
     checkGenericClassInNonGenericObjectType: false
     bootstrapFiles:
@@ -7,3 +7,5 @@ parameters:
     earlyTerminatingMethodCalls:
         Cake\Console\Shell:
             - abort
+    ignoreErrors:
+        - '#Cannot cast array\<string\>\|string to string#'
diff --git a/src/FileStorage/DataTransformer.php b/src/FileStorage/DataTransformer.php
index 943de9c..d19c018 100644
--- a/src/FileStorage/DataTransformer.php
+++ b/src/FileStorage/DataTransformer.php
@@ -73,7 +73,7 @@ public function entityToFileObject(EntityInterface $entity): FileInterface
     public function fileObjectToEntity(FileInterface $file, ?EntityInterface $entity): EntityInterface
     {
         $data = [
-            'id' => $file->uuid(),
+            'id' => $file->uuid(), //FIXME
             'model' => $file->model(),
             'foreign_key' => $file->modelId(),
             'filesize' => $file->filesize(),
diff --git a/src/Model/Behavior/FileAssociationBehavior.php b/src/Model/Behavior/FileAssociationBehavior.php
new file mode 100644
index 0000000..aaf7531
--- /dev/null
+++ b/src/Model/Behavior/FileAssociationBehavior.php
@@ -0,0 +1,126 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Burzum\FileStorage\Model\Behavior;
+
+use ArrayObject;
+use Cake\Datasource\EntityInterface;
+use Cake\Event\EventInterface;
+use Cake\ORM\Association\HasOne;
+use Cake\ORM\Behavior;
+use Laminas\Diactoros\UploadedFile;
+
+/**
+ * File Association Behavior.
+ *
+ * @author Florian Krämer
+ * @copyright 2012 - 2020 Florian Krämer
+ * @license MIT
+ */
+class FileAssociationBehavior extends Behavior
+{
+    /**
+     * @var array
+     * @inheritDoc
+     */
+    protected $_defaultConfig = [
+        'associations' => [],
+    ];
+
+    /**
+     * @inheritDoc
+     */
+    public function initialize(array $config): void
+    {
+        parent::initialize($config);
+
+        $class = get_class($this->getTable());
+        foreach ($config['associations'] as $association => $assocConfig) {
+            $associationObject = $this->getTable()->getAssociation($association);
+
+            $defaults = [
+                'replace' => $associationObject instanceof HasOne,
+                'model' => substr($class, strrpos($class, '\\') + 1, -5),
+                'property' => $this->getTable()->getAssociation($association)->getProperty(),
+            ];
+
+            $config['associations'][$association] = $assocConfig + $defaults;
+        }
+
+        $this->setConfig('associations', $config['associations']);
+    }
+
+    /**
+     * @param \Cake\Event\EventInterface $event
+     * @param \Cake\Datasource\EntityInterface $entity
+     * @param \ArrayObject $options
+     *
+     * @return void
+     */
+    public function afterSave(
+        EventInterface $event,
+        EntityInterface $entity,
+        ArrayObject $options
+    ): void {
+        $associations = $this->getConfig('associations');
+
+        foreach ($associations as $association => $assocConfig) {
+            $property = $assocConfig['property'];
+            if ($entity->{$property} === null) {
+                continue;
+            }
+
+            if ($entity->id && $entity->{$property} && $entity->{$property}->file) {
+                $file = $entity->{$property}->file;
+
+                $ok = false;
+                if (is_array($file) && $file['error'] === UPLOAD_ERR_OK) {
+                    $ok = true;
+                } elseif ($file instanceof UploadedFile && $file->getError() === UPLOAD_ERR_OK) {
+                    $ok = true;
+                }
+
+                if (!$ok) {
+                    continue;
+                }
+
+                if ($assocConfig['replace'] === true) {
+                    $this->findAndRemovePreviousFile($entity, $association, $assocConfig);
+                }
+
+                $entity->{$property}->set('collection', $assocConfig['collection']);
+                $entity->{$property}->set('model', $assocConfig['model']);
+                $entity->{$property}->set('foreign_key', $entity->id);
+
+                $this->getTable()->{$association}->saveOrFail($entity->{$property});
+            }
+        }
+    }
+
+    /**
+     * @param \Cake\Datasource\EntityInterface $entity
+     * @param string $association
+     * @param array $assocConfig
+     *
+     * @return void
+     */
+    protected function findAndRemovePreviousFile(
+        EntityInterface $entity,
+        string $association,
+        array $assocConfig
+    ): void {
+        $result = $this->getTable()->{$association}->find()
+            ->where([
+                'collection' => $assocConfig['collection'],
+                'model' => $assocConfig['model'],
+                'foreign_key' => $entity->get((string)$this->getTable()->getPrimaryKey()),
+                'id !=' => $entity->get($assocConfig['property'])->get((string)$this->getTable()->{$association}->getPrimaryKey()),
+            ])
+            ->first();
+
+        if ($result) {
+            $this->getTable()->{$association}->delete($result);
+        }
+    }
+}
diff --git a/src/Model/Behavior/FileStorageBehavior.php b/src/Model/Behavior/FileStorageBehavior.php
index 4f95446..190fb93 100644
--- a/src/Model/Behavior/FileStorageBehavior.php
+++ b/src/Model/Behavior/FileStorageBehavior.php
@@ -33,17 +33,17 @@ class FileStorageBehavior extends Behavior
     /**
      * @var \Phauthentic\Infrastructure\Storage\FileStorage
      */
-    protected FileStorage $fileStorage;
+    protected $fileStorage;
 
     /**
-     * @var \Phauthentic\Infrastructure\Storage\Processor\ProcessorInterface
+     * @var \Burzum\FileStorage\FileStorage\DataTransformerInterface
      */
-    protected ?ProcessorInterface $imageProcessor;
+    protected $transformer;
 
     /**
-     * @var \Burzum\FileStorage\FileStorage\DataTransformerInterface
+     * @var \Phauthentic\Infrastructure\Storage\Processor\ProcessorInterface
      */
-    protected DataTransformerInterface $transformer;
+    protected $processor;
 
     /**
      * Default config
@@ -55,14 +55,9 @@ class FileStorageBehavior extends Behavior
         'ignoreEmptyFile' => true,
         'fileField' => 'file',
         'fileStorage' => null,
-        'imageProcessor' => null,
+        'fileProcessor' => null,
     ];
 
-    /**
-     * @var array
-     */
-    protected array $processors = [];
-
     /**
      * @inheritDoc
      *
@@ -85,6 +80,8 @@ public function initialize(array $config): void
                 $this->getTable()
             );
         }
+
+        //$this->processors = (array)$this->getConfig('processors');
     }
 
     /**
@@ -184,11 +181,12 @@ public function afterSave(EventInterface $event, EntityInterface $entity, ArrayO
             try {
                 $file = $this->entityToFileObject($entity);
                 $file = $this->fileStorage->store($file);
+
+                // TODO: move into stack processing
                 $file = $this->processImages($file, $entity);
 
-                foreach ($this->processors as $processor) {
-                    $file = $processor->process($file);
-                }
+                $processor = $this->getFileProcessor();
+                $file = $processor->process($file);
 
                 $entity = $this->fileObjectToEntity($file, $entity);
                 $this->getTable()->save(
@@ -219,7 +217,7 @@ protected function checkEntityBeforeSave(EntityInterface $entity)
     {
         if ($entity->isNew()) {
             if (!$entity->has('model')) {
-                $entity->set('model', $this->getTable()->getTable());
+                $entity->set('model', $this->getTable()->getAlias());
             }
 
             if (!$entity->has('adapter')) {
@@ -266,7 +264,7 @@ protected function getFileInfoFromUpload(&$upload, $field = 'file')
         if (!is_array($uploadedFile)) {
             $upload['filesize'] = $uploadedFile->getSize();
             $upload['mime_type'] = $uploadedFile->getClientMediaType();
-            $upload['extension'] = pathinfo($uploadedFile->getClientFilename(), PATHINFO_EXTENSION);
+            $upload['extension'] = pathinfo((string)$uploadedFile->getClientFilename(), PATHINFO_EXTENSION);
             $upload['filename'] = $uploadedFile->getClientFilename();
         } else {
             $upload['filesize'] = $uploadedFile['size'];
@@ -285,7 +283,7 @@ protected function getFileInfoFromUpload(&$upload, $field = 'file')
      *
      * @return int Number of deleted records / files
      */
-    public function deleteAllFiles($conditions)
+    public function deleteAllFiles(array $conditions)
     {
         $table = $this->getTable();
 
@@ -334,16 +332,15 @@ public function fileObjectToEntity(FileInterface $file, ?EntityInterface $entity
      */
     public function processImages(FileInterface $file, EntityInterface $entity): FileInterface
     {
-        $imageSizes = Configure::read('FileStorage.imageVariants');
+        $imageSizes = (array)Configure::read('FileStorage.imageVariants');
         $model = $file->model();
-        $identifier = $entity->get('identifier');
+        $collection = $entity->get('collection');
 
-        if (!isset($imageSizes[$model][$identifier])) {
+        if (!isset($imageSizes[$model][$collection])) {
             return $file;
         }
 
-        $file = $file->withVariants($imageSizes[$model][$identifier]);
-        $file = $this->imageProcessor->process($file);
+        $file = $file->withVariants($imageSizes[$model][$collection]);
 
         return $file;
     }
@@ -353,20 +350,20 @@ public function processImages(FileInterface $file, EntityInterface $entity): Fil
      *
      * @return \Phauthentic\Infrastructure\Storage\Processor\ProcessorInterface
      */
-    protected function getImageProcessor(): ProcessorInterface
+    protected function getFileProcessor(): ProcessorInterface
     {
-        if ($this->imageProcessor !== null) {
-            return $this->imageProcessor;
+        if ($this->processor !== null) {
+            return $this->processor;
         }
 
-        if ($this->getConfig('imageProcessor') instanceof ProcessorInterface) {
-            $this->imageProcessor = $this->getConfig('imageProcessor');
+        if ($this->getConfig('fileProcessor') instanceof ProcessorInterface) {
+            $this->processor = $this->getConfig('fileProcessor');
         }
 
-        if ($this->imageProcessor === null) {
-            throw new RuntimeException('No image processor found');
+        if ($this->processor === null) {
+            throw new RuntimeException('No processor found');
         }
 
-        return $this->imageProcessor;
+        return $this->processor;
     }
 }
diff --git a/src/Model/Entity/FileStorage.php b/src/Model/Entity/FileStorage.php
index 4913d8a..1b063c0 100644
--- a/src/Model/Entity/FileStorage.php
+++ b/src/Model/Entity/FileStorage.php
@@ -12,6 +12,24 @@
  * @author Florian Krämer
  * @copyright 2012 - 2020 Florian Krämer
  * @license MIT
+ *
+ * @property array $variants
+ * @property array $metadata
+ * @property int $id
+ * @property int|null $user_id
+ * @property int|null $foreign_key
+ * @property string|null $model
+ * @property string|null $filename
+ * @property int|null $filesize
+ * @property string|null $mime_type
+ * @property string|null $extension
+ * @property string|null $hash
+ * @property string|null $path
+ * @property string|null $adapter
+ * @property \Cake\I18n\FrozenTime $created
+ * @property \Cake\I18n\FrozenTime $modified
+ * @property string|null $collection
+ * @property array $variant_urls
  */
 class FileStorage extends Entity implements FileStorageEntityInterface
 {
diff --git a/src/Model/Table/FileStorageTable.php b/src/Model/Table/FileStorageTable.php
index 9aa7ced..95e357b 100644
--- a/src/Model/Table/FileStorageTable.php
+++ b/src/Model/Table/FileStorageTable.php
@@ -25,6 +25,22 @@
  * @author Florian Krämer
  * @copyright 2012 - 2020 Florian Krämer
  * @license MIT
+ *
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage newEmptyEntity()
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage newEntity(array $data, array $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage[] newEntities(array $data, array $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage get($primaryKey, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage findOrCreate($search, ?callable $callback = null, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage patchEntity(\Cake\Datasource\EntityInterface $entity, array $data, array $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage[] patchEntities(iterable $entities, array $data, array $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage|false save(\Cake\Datasource\EntityInterface $entity, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage saveOrFail(\Cake\Datasource\EntityInterface $entity, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage[]|\Cake\Datasource\ResultSetInterface|false saveMany(iterable $entities, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage[]|\Cake\Datasource\ResultSetInterface saveManyOrFail(iterable $entities, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage[]|\Cake\Datasource\ResultSetInterface|false deleteMany(iterable $entities, $options = [])
+ * @method \Burzum\FileStorage\Model\Entity\FileStorage[]|\Cake\Datasource\ResultSetInterface deleteManyOrFail(iterable $entities, $options = [])
+ * @mixin \Cake\ORM\Behavior\TimestampBehavior
+ * @mixin \Burzum\FileStorage\Model\Behavior\FileStorageBehavior
  */
 class FileStorageTable extends Table
 {
diff --git a/src/Shell/ImageVersionShell.php b/src/Shell/ImageVersionShell.php
index 53fbd6f..2f6a0eb 100644
--- a/src/Shell/ImageVersionShell.php
+++ b/src/Shell/ImageVersionShell.php
@@ -25,7 +25,7 @@ class ImageVersionShell extends Shell
     /**
      * Storage Table Object
      *
-     * @var \Cake\ORM\Table|null
+     * @var \Cake\ORM\Table
      */
     public $Table;
 
@@ -200,6 +200,9 @@ public function regenerate(): void
 
         foreach ($operations as $version => $operation) {
             try {
+                if ($this->command === null) {
+                    $this->abort('No command given');
+                }
                 $this->_loop($this->command, $this->args[0], [$version => $operation], $options);
             } catch (Exception $e) {
                 $this->abort($e->getMessage());
diff --git a/src/View/Helper/ImageHelper.php b/src/View/Helper/ImageHelper.php
index e1f36f5..0ac05d6 100644
--- a/src/View/Helper/ImageHelper.php
+++ b/src/View/Helper/ImageHelper.php
@@ -88,7 +88,7 @@ public function imageUrl(FileStorageEntityInterface $image, ?string $variant = n
         }
 
         if (!$path) {
-            throw VariantDoesNotExistException::withName($variant);
+            throw VariantDoesNotExistException::withName((string)$variant);
         }
 
         $options = array_merge($this->getConfig(), $options);
diff --git a/tests/Fixture/FileStorageFixture.php b/tests/Fixture/FileStorageFixture.php
index b72d5a6..60b5d6e 100644
--- a/tests/Fixture/FileStorageFixture.php
+++ b/tests/Fixture/FileStorageFixture.php
@@ -32,13 +32,14 @@ class FileStorageFixture extends TestFixture
         'user_id' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 36],
         'foreign_key' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 36],
         'model' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 64],
+        'collection' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 128],
         'filename' => ['type' => 'string', 'null' => false, 'default' => null],
         'filesize' => ['type' => 'integer', 'null' => true, 'default' => null, 'length' => 16],
         'mime_type' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 32],
         'extension' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 32],
         'hash' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 64],
         'path' => ['type' => 'string', 'null' => true, 'default' => null],
-        'adapter' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 32, 'comment' => 'Gaufrette Storage Adapter Class'],
+        'adapter' => ['type' => 'string', 'null' => true, 'default' => null, 'length' => 32],
         'variants' => ['type' => 'json', 'null' => true, 'default' => null],
         'metadata' => ['type' => 'json', 'null' => true, 'default' => null],
         'created' => ['type' => 'datetime', 'null' => true, 'default' => null],