diff --git a/DataStorage/Cache/Connection/ConnectionAbstract.php b/DataStorage/Cache/Connection/ConnectionAbstract.php
index 83fa481f0..8baac3b3b 100644
--- a/DataStorage/Cache/Connection/ConnectionAbstract.php
+++ b/DataStorage/Cache/Connection/ConnectionAbstract.php
@@ -39,7 +39,7 @@ abstract class ConnectionAbstract implements ConnectionInterface
      * @var mixed
      * @since 1.0.0
      */
-    private $con = null;
+    protected $con = null;
 
     /**
      * Database prefix.
diff --git a/DataStorage/Database/Connection/MysqlConnection.php b/DataStorage/Database/Connection/MysqlConnection.php
index a05fc19b3..92676ab56 100644
--- a/DataStorage/Database/Connection/MysqlConnection.php
+++ b/DataStorage/Database/Connection/MysqlConnection.php
@@ -59,7 +59,7 @@ final class MysqlConnection extends ConnectionAbstract
         $this->dbdata = isset($dbdata) ? $dbdata : $this->dbdata;
 
         if (!isset($this->dbdata['db'], $this->dbdata['host'], $this->dbdata['port'], $this->dbdata['database'], $this->dbdata['login'], $this->dbdata['password'])) {
-            throw new InvalidConnectionConfigException(\json_encode($this->dbdata));
+            throw new InvalidConnectionConfigException((string) \json_encode($this->dbdata));
         }
 
         $this->close();
diff --git a/DataStorage/Database/Connection/PostgresConnection.php b/DataStorage/Database/Connection/PostgresConnection.php
index 33fa94d48..ae61b9338 100644
--- a/DataStorage/Database/Connection/PostgresConnection.php
+++ b/DataStorage/Database/Connection/PostgresConnection.php
@@ -58,7 +58,7 @@ final class PostgresConnection extends ConnectionAbstract
         $this->dbdata = isset($dbdata) ? $dbdata : $this->dbdata;
 
         if (!isset($this->dbdata['db'], $this->dbdata['host'], $this->dbdata['port'], $this->dbdata['database'], $this->dbdata['login'], $this->dbdata['password'])) {
-            throw new InvalidConnectionConfigException(\json_encode($this->dbdata));
+            throw new InvalidConnectionConfigException((string) \json_encode($this->dbdata));
         }
 
         $this->close();
diff --git a/DataStorage/Database/Connection/SQLiteConnection.php b/DataStorage/Database/Connection/SQLiteConnection.php
index 5e45f345f..23374e332 100644
--- a/DataStorage/Database/Connection/SQLiteConnection.php
+++ b/DataStorage/Database/Connection/SQLiteConnection.php
@@ -16,7 +16,7 @@ namespace phpOMS\DataStorage\Database\Connection;
 
 use phpOMS\DataStorage\Database\DatabaseStatus;
 use phpOMS\DataStorage\Database\DatabaseType;
-use phpOMS\DataStorage\Database\Query\Grammar\SqliteGrammar;
+use phpOMS\DataStorage\Database\Query\Grammar\SQLiteGrammar;
 
 /**
  * Database handler.
@@ -29,7 +29,7 @@ use phpOMS\DataStorage\Database\Query\Grammar\SqliteGrammar;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-final class SqliteConnection extends ConnectionAbstract
+final class SQLiteConnection extends ConnectionAbstract
 {
 
     /**
@@ -43,8 +43,8 @@ final class SqliteConnection extends ConnectionAbstract
      */
     public function __construct(array $dbdata)
     {
-        $this->type    = DatabaseType::MYSQL;
-        $this->grammar = new SqliteGrammar();
+        $this->type    = DatabaseType::SQLITE;
+        $this->grammar = new SQLiteGrammar();
         $this->connect($dbdata);
     }
 
@@ -65,9 +65,10 @@ final class SqliteConnection extends ConnectionAbstract
 
             $this->status = DatabaseStatus::OK;
         } catch (\PDOException $e) {
-            var_dump($e->getMessage());
             $this->status = DatabaseStatus::MISSING_DATABASE;
             $this->con    = null;
+        } finally {
+            $this->dbdata['password'] = '****';
         }
     }
 }
diff --git a/DataStorage/Database/DatabaseType.php b/DataStorage/Database/DatabaseType.php
index 2999a3ace..8fa1a2491 100644
--- a/DataStorage/Database/DatabaseType.php
+++ b/DataStorage/Database/DatabaseType.php
@@ -30,7 +30,7 @@ abstract class DatabaseType extends Enum
 {
     public const MYSQL  = 'mysql'; /* MySQL */
     public const SQLITE = 'sqlite'; /* SQLITE */
-    public const PGSQL  = 2; /* PostgreSQL */
+    public const PGSQL  = 'postgresql'; /* PostgreSQL */
     public const ORACLE = 3; /* Oracle */
     public const SQLSRV = 'mssql'; /* Microsoft SQL Server */
 }
diff --git a/DataStorage/Database/Query/Grammar/SQLiteGrammar.php b/DataStorage/Database/Query/Grammar/SQLiteGrammar.php
index d77483f85..056a8d6c5 100644
--- a/DataStorage/Database/Query/Grammar/SQLiteGrammar.php
+++ b/DataStorage/Database/Query/Grammar/SQLiteGrammar.php
@@ -24,7 +24,7 @@ use phpOMS\DataStorage\Database\Query\Builder;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class SqliteGrammar extends Grammar
+class SQLiteGrammar extends Grammar
 {
 
     /**
diff --git a/DataStorage/Database/Schema/Grammar/MysqlGrammar.php b/DataStorage/Database/Schema/Grammar/MysqlGrammar.php
index ea86d288e..43e2e9270 100644
--- a/DataStorage/Database/Schema/Grammar/MysqlGrammar.php
+++ b/DataStorage/Database/Schema/Grammar/MysqlGrammar.php
@@ -67,7 +67,7 @@ class MysqlGrammar extends Grammar
      */
     protected function compileFrom(Builder $query, array $table) : string
     {
-        $expression = $this->expressionizeTableColumn('information_schema.tables');
+        $expression = $this->expressionizeTableColumn(['information_schema.tables']);
 
         return 'FROM ' . $expression;
     }
diff --git a/DataStorage/Database/Schema/Grammar/PostgresGrammar.php b/DataStorage/Database/Schema/Grammar/PostgresGrammar.php
index 51ae131e8..6dfe5424f 100644
--- a/DataStorage/Database/Schema/Grammar/PostgresGrammar.php
+++ b/DataStorage/Database/Schema/Grammar/PostgresGrammar.php
@@ -14,7 +14,7 @@ declare(strict_types=1);
 
 namespace phpOMS\DataStorage\Database\Schema\Grammar;
 
-class PostgresGrammar
+class PostgresGrammar extends Grammar
 {
 
 }
diff --git a/DataStorage/Database/Schema/Grammar/SQLiteGrammar.php b/DataStorage/Database/Schema/Grammar/SQLiteGrammar.php
index da4a7dd52..448fe9a91 100644
--- a/DataStorage/Database/Schema/Grammar/SQLiteGrammar.php
+++ b/DataStorage/Database/Schema/Grammar/SQLiteGrammar.php
@@ -14,7 +14,7 @@ declare(strict_types=1);
 
 namespace phpOMS\DataStorage\Database\Schema\Grammar;
 
-class SQLiteGrammar
+class SQLiteGrammar extends Grammar
 {
 
 }
diff --git a/DataStorage/Session/HttpSession.php b/DataStorage/Session/HttpSession.php
index 2d66dc3a2..443fb5e38 100644
--- a/DataStorage/Session/HttpSession.php
+++ b/DataStorage/Session/HttpSession.php
@@ -50,7 +50,7 @@ class HttpSession implements SessionInterface
     /**
      * Session ID.
      *
-     * @var string|int
+     * @var string|int|null
      * @since 1.0.0
      */
     private $sid = null;
@@ -85,7 +85,7 @@ class HttpSession implements SessionInterface
         }
 
         if (!\is_bool($sid)) {
-            \session_id($sid);
+            \session_id((string) $sid);
         }
 
         $this->inactivityInterval = $inactivityInterval;
diff --git a/DataStorage/Session/SessionInterface.php b/DataStorage/Session/SessionInterface.php
index 98d3b68a5..2e8e6eb77 100644
--- a/DataStorage/Session/SessionInterface.php
+++ b/DataStorage/Session/SessionInterface.php
@@ -74,14 +74,14 @@ interface SessionInterface
     public function save() : void;
 
     /**
-     * @return int|string
+     * @return int|string|null
      *
      * @since  1.0.0
      */
     public function getSID();
 
     /**
-     * @param int|string $sid Session id
+     * @param int|string|null $sid Session id
      *
      * @return void
      *
diff --git a/Math/Stochastic/Distribution/BinomialDistribution.php b/Math/Stochastic/Distribution/BinomialDistribution.php
index ef62eb044..82a49127c 100644
--- a/Math/Stochastic/Distribution/BinomialDistribution.php
+++ b/Math/Stochastic/Distribution/BinomialDistribution.php
@@ -57,7 +57,7 @@ class BinomialDistribution
      */
     public static function getMgf(int $n, float $t, float $p) : float
     {
-        return (float) pow(1 - $p + $p * exp($t), $n);
+        return pow(1 - $p + $p * exp($t), $n);
     }
 
     /**
diff --git a/Math/Stochastic/Distribution/ChiSquaredDistribution.php b/Math/Stochastic/Distribution/ChiSquaredDistribution.php
index 80d472bcc..18547f119 100644
--- a/Math/Stochastic/Distribution/ChiSquaredDistribution.php
+++ b/Math/Stochastic/Distribution/ChiSquaredDistribution.php
@@ -31,7 +31,7 @@ class ChiSquaredDistribution
     /**
      * Chi square table.
      *
-     * @var array
+     * @var array<int, array<string, float>>
      * @since 1.0.0
      */
     public const TABLE = [
@@ -106,7 +106,7 @@ class ChiSquaredDistribution
             $df = self::getDegreesOfFreedom($dataset);
         }
 
-        if (!defined(self::TABLE[$df])) {
+        if (!defined('self::TABLE') || !array_key_exists($df, self::TABLE)) {
             throw new \Exception('Degrees of freedom not supported');
         }
 
@@ -117,7 +117,8 @@ class ChiSquaredDistribution
             }
         }
 
-        $p = 1 - ($p ?? key(end(self::TABLE[$df])));
+        $key = key(end(self::TABLE[$df]));
+        $p   = 1 - ($p ?? ($key === false ? 1 : (float) $key));
 
         return ['P' => $p, 'H0' => ($p > $significance), 'df' => $df];
     }
@@ -235,7 +236,7 @@ class ChiSquaredDistribution
             throw new \Exception('Out of bounds');
         }
 
-        return (float) pow(1 - 2 * $t, -$df / 2);
+        return pow(1 - 2 * $t, -$df / 2);
     }
 
     /**
diff --git a/Math/Stochastic/Distribution/ExponentialDistribution.php b/Math/Stochastic/Distribution/ExponentialDistribution.php
index d53ed6303..43be19014 100644
--- a/Math/Stochastic/Distribution/ExponentialDistribution.php
+++ b/Math/Stochastic/Distribution/ExponentialDistribution.php
@@ -105,7 +105,7 @@ class ExponentialDistribution
      */
     public static function getVariance(float $lambda) : float
     {
-        return (float) pow($lambda, -2);
+        return pow($lambda, -2);
     }
 
     /**
diff --git a/Math/Stochastic/Distribution/GeometricDistribution.php b/Math/Stochastic/Distribution/GeometricDistribution.php
index 84ec3bf70..fdbca94ad 100644
--- a/Math/Stochastic/Distribution/GeometricDistribution.php
+++ b/Math/Stochastic/Distribution/GeometricDistribution.php
@@ -36,7 +36,7 @@ class GeometricDistribution
      */
     public static function getPmf(float $p, int $k) : float
     {
-        return (float) pow(1 - $p, $k - 1) * $p;
+        return pow(1 - $p, $k - 1) * $p;
     }
 
     /**
diff --git a/Math/Stochastic/Distribution/PoissonDistribution.php b/Math/Stochastic/Distribution/PoissonDistribution.php
index 438982080..94d6d9088 100644
--- a/Math/Stochastic/Distribution/PoissonDistribution.php
+++ b/Math/Stochastic/Distribution/PoissonDistribution.php
@@ -147,7 +147,7 @@ class PoissonDistribution
      */
     public static function getSkewness(float $lambda) : float
     {
-        return (float) pow($lambda, -1 / 2);
+        return pow($lambda, -1 / 2);
     }
 
     /**
@@ -161,7 +161,7 @@ class PoissonDistribution
      */
     public static function getFisherInformation(float $lambda) : float
     {
-        return (float) pow($lambda, -1);
+        return pow($lambda, -1);
     }
 
     /**
@@ -175,7 +175,7 @@ class PoissonDistribution
      */
     public static function getExKurtosis(float $lambda) : float
     {
-        return (float) pow($lambda, -1);
+        return pow($lambda, -1);
     }
 
     public static function getRandom()
diff --git a/Message/Http/Request.php b/Message/Http/Request.php
index 834db20b8..8101a5efb 100644
--- a/Message/Http/Request.php
+++ b/Message/Http/Request.php
@@ -140,13 +140,16 @@ final class Request extends RequestAbstract
     {
         if (isset($_SERVER['CONTENT_TYPE'])) {
             if (\stripos($_SERVER['CONTENT_TYPE'], 'application/json') !== false) {
-                if (($json = \json_decode(($input = \file_get_contents('php://input')), true)) === false || $json === null) {
+                $input = \file_get_contents('php://input');
+                $json  = \json_decode($input === false ? '' : $input, true);
+                if ($input === false || $json === false || $json === null) {
                     throw new \Exception('Is not valid json ' . $input);
                 }
 
                 $this->data += $json;
             } elseif (\stripos($_SERVER['CONTENT_TYPE'], 'application/x-www-form-urlencoded') !== false) {
-                parse_str(file_get_contents('php://input'), $temp);
+                $content = \file_get_contents('php://input');
+                \parse_str($content === false ? '' : $content, $temp);
                 $this->data += $temp;
             }
         }
@@ -292,7 +295,7 @@ final class Request extends RequestAbstract
     {
         if ($this->browser === null) {
             $arr           = BrowserType::getConstants();
-            $httpUserAgent = strtolower($_SERVER['HTTP_USER_AGENT']);
+            $httpUserAgent = \strtolower($_SERVER['HTTP_USER_AGENT']);
 
             foreach ($arr as $key => $val) {
                 if (stripos($httpUserAgent, $val)) {
@@ -333,10 +336,10 @@ final class Request extends RequestAbstract
     {
         if ($this->os === null) {
             $arr           = OSType::getConstants();
-            $httpUserAgent = strtolower($_SERVER['HTTP_USER_AGENT']);
+            $httpUserAgent = \strtolower($_SERVER['HTTP_USER_AGENT']);
 
             foreach ($arr as $key => $val) {
-                if (stripos($httpUserAgent, $val)) {
+                if (\stripos($httpUserAgent, $val)) {
                     $this->os = $val;
 
                     return $this->os;
@@ -397,7 +400,8 @@ final class Request extends RequestAbstract
      */
     public function getBody() : string
     {
-        return \file_get_contents('php://input');
+        $body = \file_get_contents('php://input');
+        return $body === false ? '' : $body;
     }
 
     /**
diff --git a/Message/Mail/Mail.php b/Message/Mail/Mail.php
index c9618ba4f..513ea0bab 100644
--- a/Message/Mail/Mail.php
+++ b/Message/Mail/Mail.php
@@ -123,7 +123,7 @@ class Mail
     /**
      * Word wrap.
      *
-     * @var string
+     * @var int
      * @since 1.0.0
      */
     protected $wordWrap = 78;
diff --git a/Module/InstallerAbstract.php b/Module/InstallerAbstract.php
index 4a347780e..6d77f0701 100644
--- a/Module/InstallerAbstract.php
+++ b/Module/InstallerAbstract.php
@@ -115,7 +115,7 @@ class InstallerAbstract
      */
     private static function activate(DatabasePool $dbPool, InfoManager $info) : void
     {
-        /** @var ActivateAbstract $class */
+        /** @var StatusAbstract $class */
         $class = '\Modules\\' . $info->getDirectory() . '\Admin\Status';
         $class::activate($dbPool, $info);
     }
diff --git a/System/File/ContainerInterface.php b/System/File/ContainerInterface.php
index 8084f7a70..fc999e9b3 100644
--- a/System/File/ContainerInterface.php
+++ b/System/File/ContainerInterface.php
@@ -205,7 +205,7 @@ interface ContainerInterface
      * @param bool   $recursive Consider subdirectories
      * @param array  $ignore    Files/paths to ignore (no regex)
      *
-     * @return string
+     * @return int
      *
      * @since  1.0.0
      */
diff --git a/Utils/IO/Zip/Gz.php b/Utils/IO/Zip/Gz.php
index 47e3ea97f..922a2ea6e 100644
--- a/Utils/IO/Zip/Gz.php
+++ b/Utils/IO/Zip/Gz.php
@@ -31,23 +31,25 @@ class Gz implements ArchiveInterface
      */
     public static function pack($source, string $destination, bool $overwrite = true) : bool
     {
-        $destination = \str_replace('\\', '/', realpath($destination));
+        $destination = \str_replace('\\', '/', $destination);
         if (!$overwrite && \file_exists($destination)) {
             return false;
         }
 
-        if (($gz = gzopen($destination, 'w')) === false) {
+        $gz  = \gzopen($destination, 'w');
+        $src = \fopen($source, 'r');
+        if ($gz === false || $src === false) {
             return false;
         }
 
-        $src = fopen($source, 'r');
-        while (!feof($src)) {
-            gzwrite($gz, fread($src, 4096));
+        while (!\feof($src)) {
+            $read = \fread($src, 4096);
+            \gzwrite($gz, $read === false ? '' : $read);
         }
 
-        fclose($src);
+        \fclose($src);
 
-        return gzclose($gz);
+        return \gzclose($gz);
     }
 
     /**
@@ -55,22 +57,23 @@ class Gz implements ArchiveInterface
      */
     public static function unpack(string $source, string $destination) : bool
     {
-        $destination = \str_replace('\\', '/', realpath($destination));
-        if (file_exists($destination)) {
+        $destination = \str_replace('\\', '/', $destination);
+        if (\file_exists($destination)) {
             return false;
         }
 
-        if (($gz = gzopen($source, 'w')) === false) {
+        $gz   = \gzopen($source, 'w');
+        $dest = \fopen($destination, 'w');
+        if ($gz === false || $dest === false) {
             return false;
         }
 
-        $dest = fopen($destination, 'w');
-        while (!gzeof($gz)) {
-            fwrite($dest, gzread($gz, 4096));
+        while (!\gzeof($gz)) {
+            \fwrite($dest, \gzread($gz, 4096));
         }
 
-        fclose($dest);
+        \fclose($dest);
 
-        return gzclose($gz);
+        return \gzclose($gz);
     }
 }
diff --git a/Utils/TaskSchedule/Cron.php b/Utils/TaskSchedule/Cron.php
index 37171fee6..8279c7f63 100644
--- a/Utils/TaskSchedule/Cron.php
+++ b/Utils/TaskSchedule/Cron.php
@@ -39,7 +39,7 @@ class Cron extends SchedulerAbstract
      */
     private function run(string $cmd) : string
     {
-        $cmd = 'cd ' . escapeshellarg(\dirname(self::$bin)) . ' && ' . basename(self::$bin) . ' ' . $cmd;
+        $cmd = 'cd ' . \escapeshellarg(\dirname(self::$bin)) . ' && ' . \basename(self::$bin) . ' ' . $cmd;
 
         $pipes = [];
         $desc  = [
@@ -47,15 +47,19 @@ class Cron extends SchedulerAbstract
             2 => ['pipe', 'w'],
         ];
 
-        $resource = proc_open($cmd, $desc, $pipes, __DIR__, null);
-        $stdout   = stream_get_contents($pipes[1]);
-        $stderr   = stream_get_contents($pipes[2]);
+        $resource = \proc_open($cmd, $desc, $pipes, __DIR__, null);
+        $stdout   = \stream_get_contents($pipes[1]);
+        $stderr   = \stream_get_contents($pipes[2]);
 
         foreach ($pipes as $pipe) {
-            fclose($pipe);
+            \fclose($pipe);
         }
 
-        $status = trim((string) proc_close($resource));
+        if ($resource === false) {
+            throw new \Exception();
+        }
+
+        $status = \proc_close($resource);
 
         if ($status == -1) {
             throw new \Exception($stderr);
@@ -88,8 +92,8 @@ class Cron extends SchedulerAbstract
 
         $jobs = [];
         foreach ($lines as $line) {
-            if ($line !== '' && strrpos($line, '#', -strlen($line)) === false) {
-                $jobs[] = CronJob::createWith(str_getcsv($line, ' '));
+            if ($line !== '' && \strrpos($line, '#', -\strlen($line)) === false) {
+                $jobs[] = CronJob::createWith(\str_getcsv($line, ' '));
             }
         }
 
@@ -107,18 +111,18 @@ class Cron extends SchedulerAbstract
         if ($exact) {
             $jobs = [];
             foreach ($lines as $line) {
-                $csv = str_getcsv($line, ' ');
+                $csv = \str_getcsv($line, ' ');
 
-                if ($line !== '' && strrpos($line, '#', -strlen($line)) === false && $csv[5] === $name) {
+                if ($line !== '' && \strrpos($line, '#', -\strlen($line)) === false && $csv[5] === $name) {
                     $jobs[] = CronJob::createWith($csv);
                 }
             }
         } else {
             $jobs = [];
             foreach ($lines as $line) {
-                $csv = str_getcsv($line, ' ');
+                $csv = \str_getcsv($line, ' ');
 
-                if ($line !== '' && strrpos($line, '#', -strlen($line)) === false && \stripos($csv[5], $name) !== false) {
+                if ($line !== '' && \strrpos($line, '#', -\strlen($line)) === false && \stripos($csv[5], $name) !== false) {
                     $jobs[] = CronJob::createWith($csv);
                 }
             }