diff --git a/Account/NullGroup.php b/Account/NullGroup.php
new file mode 100644
index 000000000..0baee204f
--- /dev/null
+++ b/Account/NullGroup.php
@@ -0,0 +1,27 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   phpOMS\Account
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Account;
+
+/**
+ * Null account class.
+ *
+ * @package phpOMS\Account
+ * @license OMS License 1.0
+ * @link    https://orange-management.org
+ * @since   1.0.0
+ */
+final class NullGroup extends Group
+{
+}
diff --git a/Business/Finance/FinanceFormulas.php b/Business/Finance/FinanceFormulas.php
index 5d11cd65d..efa8f0c3b 100644
--- a/Business/Finance/FinanceFormulas.php
+++ b/Business/Finance/FinanceFormulas.php
@@ -856,7 +856,7 @@ final class FinanceFormulas
     }
 
     /**
-     * Free Cash Flow to Equity (FCFE)
+     * Free Cash Flow to Equity (FCFE = FCFF - dept payments)
      *
      * @param float $income    Net income
      * @param float $depamo    Depreciation & amortisation
@@ -948,7 +948,9 @@ final class FinanceFormulas
     }
 
     /**
-     * Future Value Factor
+     * Geometric mean of return values
+     *
+     * Also known as compounded annual growth rate.
      *
      * @param array<float|int> $r Rate of return
      *
@@ -1252,7 +1254,7 @@ final class FinanceFormulas
      *
      * @since 1.0.0
      */
-    public static function getRateOfOnflation(float $newCPI, float $oldCPI) : float
+    public static function getRateOfInflation(float $newCPI, float $oldCPI) : float
     {
         return $newCPI / $oldCPI - 1;
     }
diff --git a/tests/Account/NullGroupTest.php b/tests/Account/NullGroupTest.php
new file mode 100644
index 000000000..4ed9e5e2c
--- /dev/null
+++ b/tests/Account/NullGroupTest.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\tests\Account;
+
+require_once __DIR__ . '/../Autoloader.php';
+
+use phpOMS\Account\NullGroup;
+
+/**
+ * @internal
+ */
+class NullGroupTest extends \PHPUnit\Framework\TestCase
+{
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\phpOMS\Account\Group', new NullGroup());
+    }
+}
diff --git a/tests/Algorithm/Clustering/KmeansTest.php b/tests/Algorithm/Clustering/KmeansTest.php
index 60470943c..d78b67080 100644
--- a/tests/Algorithm/Clustering/KmeansTest.php
+++ b/tests/Algorithm/Clustering/KmeansTest.php
@@ -12,17 +12,21 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\Clustering;
+namespace phpOMS\tests\Algorithm\Clustering;
 
 use phpOMS\Algorithm\Clustering\Kmeans;
+use phpOMS\Algorithm\Clustering\Point;
 
 /**
- * @testdox phpOMS\Algorithm\Clustering\Kmeans: Test the kmeans clustering implementation
+ * @testdox phpOMS\tests\Algorithm\Clustering\KmeansTest: Clustering points/elements with the K-means algorithm
  *
  * @internal
  */
 class KmeansTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The clustering of points and dynamic check of new points works as expected
+     */
     public function testKmeans() : void
     {
         $result = false;
diff --git a/tests/Algorithm/Clustering/PointTest.php b/tests/Algorithm/Clustering/PointTest.php
index 71b4fad51..f8e8fc6e7 100644
--- a/tests/Algorithm/Clustering/PointTest.php
+++ b/tests/Algorithm/Clustering/PointTest.php
@@ -12,17 +12,20 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\Clustering;
+namespace phpOMS\tests\Algorithm\Clustering;
 
 use phpOMS\Algorithm\Clustering\Point;
 
 /**
- * @testdox phpOMS\Algorithm\Clustering\Point: Test the point for the clustering implementation
+ * @testdox phpOMS\tests\Algorithm\Clustering\PointTest: Default point in a cluster
  *
  * @internal
  */
 class PointTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The point has the expected default values after initialization
+     */
     public function testDefault() : void
     {
         $point = new Point([3.0, 2.0], 'abc');
@@ -34,7 +37,10 @@ class PointTest extends \PHPUnit\Framework\TestCase
         self::assertEquals('abc', $point->getName());
     }
 
-    public function testSetGet() : void
+    /**
+     * @testdox Coordinates of a point can be changed
+     */
+    public function testChangeCoordinates() : void
     {
         $point = new Point([3.0, 2.0], 'abc');
 
@@ -44,6 +50,14 @@ class PointTest extends \PHPUnit\Framework\TestCase
         self::assertEquals([4.0, 1.0], $point->getCoordinates());
         self::assertEquals(4.0, $point->getCoordinate(0));
         self::assertEquals(1.0, $point->getCoordinate(1));
+    }
+
+    /**
+     * @testdox The group/cluster of a point can be changed
+     */
+    public function testChangeGroup() : void
+    {
+        $point = new Point([3.0, 2.0], 'abc');
 
         $point->setGroup(2);
         self::assertEquals(2, $point->getGroup());
diff --git a/tests/Algorithm/CoinMatching/MinimumCoinProblemTest.php b/tests/Algorithm/CoinMatching/MinimumCoinProblemTest.php
index 1e6310900..9a1b892a2 100644
--- a/tests/Algorithm/CoinMatching/MinimumCoinProblemTest.php
+++ b/tests/Algorithm/CoinMatching/MinimumCoinProblemTest.php
@@ -12,19 +12,22 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\CoinMatching;
+namespace phpOMS\tests\Algorithm\CoinMatching;
 
 use phpOMS\Algorithm\CoinMatching\MinimumCoinProblem;
 
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\Algorithm\CoinMatching\MinimumCoinProblem: Test coin matching a value problem
+ * @testdox phpOMS\tests\Algorithm\CoinMatching\MinimumCoinProblemTest: Match a value by using the minimum quantity of available sub values (Minimum Coin Problem)
  *
  * @internal
  */
 class MinimumCoinProblemTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox A value is matched with the minimum quantity of avialable coins.
+     */
     public function testMinimumCoins() : void
     {
         self::assertEquals(
diff --git a/tests/Algorithm/JobScheduling/JobTest.php b/tests/Algorithm/JobScheduling/JobTest.php
index 60912a1b5..2ee0d506d 100644
--- a/tests/Algorithm/JobScheduling/JobTest.php
+++ b/tests/Algorithm/JobScheduling/JobTest.php
@@ -12,17 +12,20 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\JobScheduling;
+namespace phpOMS\tests\Algorithm\JobScheduling;
 
 use phpOMS\Algorithm\JobScheduling\Job;
 
 /**
- * @testdox phpOMS\Algorithm\JobScheduling\Job: Test the job for the JobScheduling implementations
+ * @testdox phpOMS\tests\Algorithm\JobScheduling\JobTest: Default job for the job scheduling
  *
  * @internal
  */
 class JobTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The job has the expected values after initialization
+     */
     public function testDefault() : void
     {
         $item = new Job(3.0, new \DateTime('now'), null, 'abc');
diff --git a/tests/Algorithm/JobScheduling/WeightedTest.php b/tests/Algorithm/JobScheduling/WeightedTest.php
index 752b07ace..af33db637 100644
--- a/tests/Algorithm/JobScheduling/WeightedTest.php
+++ b/tests/Algorithm/JobScheduling/WeightedTest.php
@@ -12,18 +12,22 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\JobScheduling;
+namespace phpOMS\tests\Algorithm\JobScheduling;
 
 use phpOMS\Algorithm\JobScheduling\Weighted;
+use phpOMS\Algorithm\JobScheduling\Job;
 
 /**
- * @testdox phpOMS\Algorithm\JobScheduling\Weighted: Test the job for the JobScheduling implementations
+ * @testdox phpOMS\tests\Algorithm\JobScheduling\WeightedTest: Job scheduling based on values/profit
  *
  * @internal
  */
 class WeightedTest extends \PHPUnit\Framework\TestCase
 {
-    public function testDefault() : void
+    /**
+     * @testdox The optimal job combination is selected to maximize the value/profit without overlapping jobs
+     */
+    public function testNoOverlappingScheduling() : void
     {
         $jobs = [
             new Job(20, new \DateTime('2003-01-01'), new \DateTime('2010-01-01'), 'A'),
@@ -50,6 +54,9 @@ class WeightedTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A job list with only one job simply returns one job
+     */
     public function testSmallList() : void
     {
         $jobs = [
diff --git a/tests/Algorithm/Knapsack/BackpackTest.php b/tests/Algorithm/Knapsack/BackpackTest.php
index 2630d3d5b..3e5e30dc5 100644
--- a/tests/Algorithm/Knapsack/BackpackTest.php
+++ b/tests/Algorithm/Knapsack/BackpackTest.php
@@ -12,17 +12,21 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\Knapsack;
+namespace phpOMS\tests\Algorithm\Knapsack;
 
 use phpOMS\Algorithm\Knapsack\Backpack;
+use phpOMS\Algorithm\Knapsack\Item;
 
 /**
- * @testdox phpOMS\Algorithm\Knapsack\Backpack: Test the backpack for the Knapsack implementations
+ * @testdox phpOMS\tests\Algorithm\Knapsack\BackpackTest: The default backpack or basket which holds all items for the Knapsack algorithm
  *
  * @internal
  */
 class BackpackTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The backpack has the expected values after initialization
+     */
     public function testDefault() : void
     {
         $backpack = new Backpack(3.0);
@@ -33,7 +37,10 @@ class BackpackTest extends \PHPUnit\Framework\TestCase
         self::assertEquals([], $backpack->getItems());
     }
 
-    public function testGetSet() : void
+    /**
+     * @testdox Items can be added to the backpack and automatically change the value and cost the backpack contains
+     */
+    public function testAddItems() : void
     {
         $backpack = new Backpack(3.0);
         $backpack->addItem(new Item(2, 1), 2);
diff --git a/tests/Algorithm/Knapsack/BoundedTest.php b/tests/Algorithm/Knapsack/BoundedTest.php
index 3038ca8f8..35b83b7aa 100644
--- a/tests/Algorithm/Knapsack/BoundedTest.php
+++ b/tests/Algorithm/Knapsack/BoundedTest.php
@@ -12,17 +12,22 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\Knapsack;
+namespace phpOMS\tests\Algorithm\Knapsack;
 
 use phpOMS\Algorithm\Knapsack\Bounded;
+use phpOMS\Algorithm\Knapsack\Backpack;
+use phpOMS\Algorithm\Knapsack\Item;
 
 /**
- * @testdox phpOMS\Algorithm\Knapsack\Bounded: Test the continuous Knapsack implementations
+ * @testdox phpOMS\tests\Algorithm\Knapsack\BoundedTest: A Knapsack implementation for discrete quantities, values and costs and bounded item quantities
  *
  * @internal
  */
 class BoundedTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The optimal item selection in a backpack is calculated in order to optimize the value/profit while considering the available capacity/cost limit
+     */
     public function testBackpacking() : void
     {
         $items = [
diff --git a/tests/Algorithm/Knapsack/ContinuousTest.php b/tests/Algorithm/Knapsack/ContinuousTest.php
index f08fcc9a8..9e0cc2248 100644
--- a/tests/Algorithm/Knapsack/ContinuousTest.php
+++ b/tests/Algorithm/Knapsack/ContinuousTest.php
@@ -12,17 +12,22 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\Knapsack;
+namespace phpOMS\tests\Algorithm\Knapsack;
 
 use phpOMS\Algorithm\Knapsack\Continuous;
+use phpOMS\Algorithm\Knapsack\Backpack;
+use phpOMS\Algorithm\Knapsack\Item;
 
 /**
- * @testdox phpOMS\Algorithm\Knapsack\Continuous: Test the continuous Knapsack implementations
+ * @testdox phpOMS\tests\Algorithm\Knapsack\ContinuousTest: A Knapsack implementation for continuous quantities, values and costs
  *
  * @internal
  */
 class ContinuousTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The optimal item selection in a backpack is calculated in order to optimize the value/profit while considering the available capacity/cost limit [discrete quantities]
+     */
     public function testBackpacking() : void
     {
         $items = [
@@ -60,6 +65,9 @@ class ContinuousTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox The optimal item selection in a backpack is calculated in order to optimize the value/profit while considering the available capacity/cost limit [continuous quantities]
+     */
     public function testBackpackingAlternative() : void
     {
         $items = [
diff --git a/tests/Algorithm/Knapsack/ItemTest.php b/tests/Algorithm/Knapsack/ItemTest.php
index 1d107bcc0..d19ef8228 100644
--- a/tests/Algorithm/Knapsack/ItemTest.php
+++ b/tests/Algorithm/Knapsack/ItemTest.php
@@ -12,17 +12,20 @@
  */
 declare(strict_types=1);
 
-namespace phpOMS\Algorithm\Knapsack;
+namespace phpOMS\tests\Algorithm\Knapsack;
 
 use phpOMS\Algorithm\Knapsack\Item;
 
 /**
- * @testdox phpOMS\Algorithm\Knapsack\Item: Test the item for the Knapsack implementations
+ * @testdox phpOMS\tests\Algorithm\Knapsack\ItemTest: The default item to be added to the backpack or basket
  *
  * @internal
  */
 class ItemTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The item has the expected values after initialization
+     */
     public function testDefault() : void
     {
         $item = new Item(3.0, 2.0, 'abc');
diff --git a/tests/Algorithm/PathFinding/AStarTest.php b/tests/Algorithm/PathFinding/AStarTest.php
index 8997e2841..77d3dccfe 100644
--- a/tests/Algorithm/PathFinding/AStarTest.php
+++ b/tests/Algorithm/PathFinding/AStarTest.php
@@ -23,7 +23,7 @@ use phpOMS\Algorithm\PathFinding\AStar;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\PathFinding: jump point search test
+ * @testdox phpOMS\tests\Algorithm\PathFinding\AStarTest: AStar path finding
  *
  * @internal
  */
@@ -67,6 +67,9 @@ class AStarTest extends \PHPUnit\Framework\TestCase
         }
     }
 
+    /**
+     * @testdox The correct path is found for diagonal movement
+     */
     public function testPathFindingDiagonal() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, AStarNode::class);
@@ -106,6 +109,9 @@ class AStarTest extends \PHPUnit\Framework\TestCase
         ], $this->gridArray);
     }
 
+    /**
+     * @testdox The correct path is found for straight movement
+     */
     public function testPathFindingStraight() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, AStarNode::class);
@@ -145,6 +151,9 @@ class AStarTest extends \PHPUnit\Framework\TestCase
         ], $this->gridArray);
     }
 
+    /**
+     * @testdox The correct path is found for diagonal movement [one obstacle]
+     */
     public function testPathFindingDiagonalOneObstacle() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, AStarNode::class);
@@ -184,6 +193,9 @@ class AStarTest extends \PHPUnit\Framework\TestCase
         ], $this->gridArray);
     }
 
+    /**
+     * @testdox The correct path is found for diagonal movement [no obstacle]
+     */
     public function testPathFindingDiagonalNoObstacle() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, AStarNode::class);
diff --git a/tests/Algorithm/PathFinding/JumpPointSearchTest.php b/tests/Algorithm/PathFinding/JumpPointSearchTest.php
index 10f484f6e..1acca0cf4 100644
--- a/tests/Algorithm/PathFinding/JumpPointSearchTest.php
+++ b/tests/Algorithm/PathFinding/JumpPointSearchTest.php
@@ -23,7 +23,7 @@ use phpOMS\Algorithm\PathFinding\JumpPointSearch;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\PathFinding: jump point search test
+ * @testdox phpOMS\tests\Algorithm\PathFinding\JumpPointSearchTest: JumpPoint path finding
  *
  * @internal
  */
@@ -67,6 +67,9 @@ class JumpPointSearchTest extends \PHPUnit\Framework\TestCase
         }
     }
 
+    /**
+     * @testdox The correct path is found for diagonal movement
+     */
     public function testPathFindingDiagonal() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, JumpPointNode::class);
@@ -106,6 +109,9 @@ class JumpPointSearchTest extends \PHPUnit\Framework\TestCase
         ], $this->gridArray);
     }
 
+    /**
+     * @testdox The correct path is found for straight movement
+     */
     public function testPathFindingStraight() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, JumpPointNode::class);
@@ -145,6 +151,9 @@ class JumpPointSearchTest extends \PHPUnit\Framework\TestCase
         ], $this->gridArray);
     }
 
+    /**
+     * @testdox The correct path is found for diagonal movement [one obstacle]
+     */
     public function testPathFindingDiagonalOneObstacle() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, JumpPointNode::class);
@@ -184,6 +193,9 @@ class JumpPointSearchTest extends \PHPUnit\Framework\TestCase
         ], $this->gridArray);
     }
 
+    /**
+     * @testdox The correct path is found for diagonal movement [no obstacle]
+     */
     public function testPathFindingDiagonalNoObstacle() : void
     {
         $grid = Grid::createGridFromArray($this->gridArray, JumpPointNode::class);
diff --git a/tests/Algorithm/Sort/BitonicSortTest.php b/tests/Algorithm/Sort/BitonicSortTest.php
index 7a882b4f5..7da438e1c 100644
--- a/tests/Algorithm/Sort/BitonicSortTest.php
+++ b/tests/Algorithm/Sort/BitonicSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Bitonic sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\BitonicSortTest: Bitonic sort
  *
  * @internal
  */
@@ -38,6 +38,9 @@ class BitonicSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -46,6 +49,9 @@ class BitonicSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = BitonicSort::sort($this->list);
@@ -58,6 +64,9 @@ class BitonicSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = BitonicSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/BubbleSortTest.php b/tests/Algorithm/Sort/BubbleSortTest.php
index d1df8641c..2fddebd99 100644
--- a/tests/Algorithm/Sort/BubbleSortTest.php
+++ b/tests/Algorithm/Sort/BubbleSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Bubble sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\BubbleSortTest: Bubble sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class BubbleSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class BubbleSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = BubbleSort::sort($this->list);
@@ -59,6 +65,9 @@ class BubbleSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = BubbleSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/BucketSortTest.php b/tests/Algorithm/Sort/BucketSortTest.php
index f53b28590..ad4b86b16 100644
--- a/tests/Algorithm/Sort/BucketSortTest.php
+++ b/tests/Algorithm/Sort/BucketSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Bucket sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\BucketSortTest: Bucket sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class BucketSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class BucketSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = BucketSort::sort($this->list, 2, \phpOMS\Algorithm\Sort\SelectionSort::class);
@@ -59,6 +65,9 @@ class BucketSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = BucketSort::sort($this->list, 2, \phpOMS\Algorithm\Sort\SelectionSort::class, SortOrder::DESC);
@@ -71,6 +80,9 @@ class BucketSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox If no buckets are specified the elements cannot be sorted and an empty result is returned
+     */
     public function testNoBuckets() : void
     {
         $newList = BucketSort::sort($this->list, 0, \phpOMS\Algorithm\Sort\SelectionSort::class);
diff --git a/tests/Algorithm/Sort/CocktailShakerSortTest.php b/tests/Algorithm/Sort/CocktailShakerSortTest.php
index 17a19419c..1b6cb3832 100644
--- a/tests/Algorithm/Sort/CocktailShakerSortTest.php
+++ b/tests/Algorithm/Sort/CocktailShakerSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: CocktailShaker sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\CocktailShakerSortTest: CocktailShaker sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class CocktailShakerSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class CocktailShakerSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = CocktailShakerSort::sort($this->list);
@@ -59,6 +65,9 @@ class CocktailShakerSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = CocktailShakerSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/CombSortTest.php b/tests/Algorithm/Sort/CombSortTest.php
index 00063f81e..bb846279f 100644
--- a/tests/Algorithm/Sort/CombSortTest.php
+++ b/tests/Algorithm/Sort/CombSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Comb sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\CombSortTest: Comb sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class CombSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class CombSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = CombSort::sort($this->list);
@@ -59,6 +65,9 @@ class CombSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = CombSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/CycleSortTest.php b/tests/Algorithm/Sort/CycleSortTest.php
index d05d47e9a..3ca728b87 100644
--- a/tests/Algorithm/Sort/CycleSortTest.php
+++ b/tests/Algorithm/Sort/CycleSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Cycle sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\CycleSortTest: Cycle sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class CycleSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class CycleSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = CycleSort::sort($this->list);
@@ -59,6 +65,9 @@ class CycleSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = CycleSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/GnomeSortTest.php b/tests/Algorithm/Sort/GnomeSortTest.php
index 623d7baca..471dae9d6 100644
--- a/tests/Algorithm/Sort/GnomeSortTest.php
+++ b/tests/Algorithm/Sort/GnomeSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Gnome sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\GnomeSortTest: Gnome sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class GnomeSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class GnomeSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = GnomeSort::sort($this->list);
@@ -59,6 +65,9 @@ class GnomeSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = GnomeSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/HeapSortTest.php b/tests/Algorithm/Sort/HeapSortTest.php
index 121842717..7e06dbce0 100644
--- a/tests/Algorithm/Sort/HeapSortTest.php
+++ b/tests/Algorithm/Sort/HeapSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Heap sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\HeapSortTest: Heap sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class HeapSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class HeapSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = HeapSort::sort($this->list);
@@ -59,6 +65,9 @@ class HeapSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = HeapSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/InsertionSortTest.php b/tests/Algorithm/Sort/InsertionSortTest.php
index 06b74ca89..05a32998d 100644
--- a/tests/Algorithm/Sort/InsertionSortTest.php
+++ b/tests/Algorithm/Sort/InsertionSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Insertion sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\InsertionSortTest: Insertion sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class InsertionSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class InsertionSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = InsertionSort::sort($this->list);
@@ -59,6 +65,9 @@ class InsertionSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = InsertionSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/IntroSortTest.php b/tests/Algorithm/Sort/IntroSortTest.php
index edbb4b0c4..835e0b256 100644
--- a/tests/Algorithm/Sort/IntroSortTest.php
+++ b/tests/Algorithm/Sort/IntroSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Intro sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\IntroSortTest: Intro sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class IntroSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class IntroSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = IntroSort::sort($this->list);
@@ -59,6 +65,9 @@ class IntroSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = IntroSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/MergeSortTest.php b/tests/Algorithm/Sort/MergeSortTest.php
index 2c3363e4f..335980b94 100644
--- a/tests/Algorithm/Sort/MergeSortTest.php
+++ b/tests/Algorithm/Sort/MergeSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Merge sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\MergeSortTest: Merge sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class MergeSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class MergeSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = MergeSort::sort($this->list);
@@ -59,6 +65,9 @@ class MergeSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = MergeSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/OddEvenSortTest.php b/tests/Algorithm/Sort/OddEvenSortTest.php
index ea817d006..90de4bf7d 100644
--- a/tests/Algorithm/Sort/OddEvenSortTest.php
+++ b/tests/Algorithm/Sort/OddEvenSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: OddEven sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\OddEvenSortTest: OddEven sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class OddEvenSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class OddEvenSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = OddEvenSort::sort($this->list);
@@ -59,6 +65,9 @@ class OddEvenSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = OddEvenSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/PancakeSortTest.php b/tests/Algorithm/Sort/PancakeSortTest.php
index 4b01c643b..784593f5f 100644
--- a/tests/Algorithm/Sort/PancakeSortTest.php
+++ b/tests/Algorithm/Sort/PancakeSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Pancake sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\PancakeSortTest: Pancake sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class PancakeSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class PancakeSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = PancakeSort::sort($this->list);
@@ -59,6 +65,9 @@ class PancakeSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = PancakeSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/QuickSortTest.php b/tests/Algorithm/Sort/QuickSortTest.php
index ba650c139..e6304176a 100644
--- a/tests/Algorithm/Sort/QuickSortTest.php
+++ b/tests/Algorithm/Sort/QuickSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Quick sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\QuickSortTest: Quick sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class QuickSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class QuickSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = QuickSort::sort($this->list);
@@ -59,6 +65,9 @@ class QuickSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = QuickSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/SelectionSortTest.php b/tests/Algorithm/Sort/SelectionSortTest.php
index 8369b25a3..3e445f045 100644
--- a/tests/Algorithm/Sort/SelectionSortTest.php
+++ b/tests/Algorithm/Sort/SelectionSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Selection sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\SelectionSortTest: Selection sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class SelectionSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class SelectionSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = SelectionSort::sort($this->list);
@@ -59,6 +65,9 @@ class SelectionSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = SelectionSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/ShellSortTest.php b/tests/Algorithm/Sort/ShellSortTest.php
index a2c209ff3..e4081752f 100644
--- a/tests/Algorithm/Sort/ShellSortTest.php
+++ b/tests/Algorithm/Sort/ShellSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Shell sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\ShellSortTest: Shell sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class ShellSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class ShellSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = ShellSort::sort($this->list);
@@ -59,6 +65,9 @@ class ShellSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = ShellSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/StoogeSortTest.php b/tests/Algorithm/Sort/StoogeSortTest.php
index d32955eb3..bde8bcb8d 100644
--- a/tests/Algorithm/Sort/StoogeSortTest.php
+++ b/tests/Algorithm/Sort/StoogeSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Stooge sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\StoogeSortTest: Stooge sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class StoogeSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class StoogeSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = StoogeSort::sort($this->list);
@@ -59,6 +65,9 @@ class StoogeSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = StoogeSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Algorithm/Sort/TimSortTest.php b/tests/Algorithm/Sort/TimSortTest.php
index e9d2e643a..e0205a9f5 100644
--- a/tests/Algorithm/Sort/TimSortTest.php
+++ b/tests/Algorithm/Sort/TimSortTest.php
@@ -20,7 +20,7 @@ use phpOMS\Algorithm\Sort\SortOrder;
 require_once __DIR__ . '/../../Autoloader.php';
 
 /**
- * @testdox phpOMS\tests\Algorithm\Sort: Tim sort test
+ * @testdox phpOMS\tests\Algorithm\Sort\TimSortTest: Tim sort
  *
  * @internal
  */
@@ -39,6 +39,9 @@ class TimSortTest extends \PHPUnit\Framework\TestCase
         ];
     }
 
+    /**
+     * @testdox A list with one element returns the list with the element itself
+     */
     public function testSmallList() : void
     {
         $smallList = [new NumericElement(3)];
@@ -47,6 +50,9 @@ class TimSortTest extends \PHPUnit\Framework\TestCase
         self::assertEquals($smallList, $newList);
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in ASC order
+     */
     public function testSortASC() : void
     {
         $newList = TimSort::sort($this->list);
@@ -59,6 +65,9 @@ class TimSortTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox A list ot elements can be sorted in DESC order
+     */
     public function testSortDESC() : void
     {
         $newList = TimSort::sort($this->list, SortOrder::DESC);
diff --git a/tests/Business/Finance/DepreciationTest.php b/tests/Business/Finance/DepreciationTest.php
index 51f182d9f..98444a829 100644
--- a/tests/Business/Finance/DepreciationTest.php
+++ b/tests/Business/Finance/DepreciationTest.php
@@ -17,7 +17,7 @@ namespace phpOMS\tests\Business\Finance;
 use phpOMS\Business\Finance\Depreciation;
 
 /**
- * @testdox phpOMS\Business\Finance\DepreciationTest: Depreciation calculations
+ * @testdox phpOMS\tests\Business\Finance\DepreciationTest: Depreciation calculations
  *
  * @internal
  */
diff --git a/tests/Business/Finance/FinanceFormulasTest.php b/tests/Business/Finance/FinanceFormulasTest.php
index d88a63dc5..127511e50 100644
--- a/tests/Business/Finance/FinanceFormulasTest.php
+++ b/tests/Business/Finance/FinanceFormulasTest.php
@@ -17,7 +17,7 @@ namespace phpOMS\tests\Business\Finance;
 use phpOMS\Business\Finance\FinanceFormulas;
 
 /**
- * @testdox phpOMS\Business\Finance\FinanceFormulasTest: Finance formulas
+ * @testdox phpOMS\tests\Business\Finance\FinanceFormulasTest: Finance formulas
  *
  * @internal
  */
@@ -229,20 +229,33 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEquals(500 / 1000, FinanceFormulas::getDebtToIncomeRatio(500, 1000));
     }
 
+    /**
+     * @testdox Return on balance statement positions are correct (e.g. return on assets, on equity)
+     */
+    public function testReturnOnBalancePositions() : void
+    {
+        self::assertEquals(500 / 1000, FinanceFormulas::getReturnOnAssets(500, 1000));
+        self::assertEquals(500 / 1000, FinanceFormulas::getReturnOnEquity(500, 1000));
+        self::assertEquals(500 / 1000 - 1, FinanceFormulas::getReturnOnInvestment(500, 1000));
+    }
+
+    /**
+     * @testdox Balance / P&L ratios are correct (e.g. inventory turnover, net profit margin)
+     */
+    public function testBalancePLRatios() : void
+    {
+        self::assertEquals(500 / 1000, FinanceFormulas::getInventoryTurnoverRatio(500, 1000));
+        self::assertEquals(500 / 1000, FinanceFormulas::getNetProfitMargin(500, 1000));
+        self::assertEquals(500 / 1000, FinanceFormulas::getReceivablesTurnoverRatio(500, 1000));
+    }
+
     public function testRatios() : void
     {
         self::assertEquals(500 / 1000, FinanceFormulas::getInterestCoverageRatio(500, 1000));
-        self::assertEquals(500 / 1000, FinanceFormulas::getInventoryTurnoverRatio(500, 1000));
-        self::assertEquals(500 / 1000, FinanceFormulas::getNetProfitMargin(500, 1000));
-
-        self::assertEquals(500 / 1000, FinanceFormulas::getReturnOnAssets(500, 1000));
-        self::assertEquals(500 / 1000, FinanceFormulas::getReturnOnEquity(500, 1000));
-        self::assertEquals(500 / 1000, FinanceFormulas::getReceivablesTurnoverRatio(500, 1000));
         self::assertEquals(500 / 1000, FinanceFormulas::getQuickRatio(500, 1000));
 
-        self::assertEquals(500 / 1000 - 1, FinanceFormulas::getReturnOnInvestment(500, 1000));
         self::assertEquals((500 - 300) / 500, FinanceFormulas::getRetentionRatio(500, 300));
-        self::assertEquals(500 / 1000 - 1, FinanceFormulas::getRateOfOnflation(500, 1000));
+        self::assertEquals(500 / 1000 - 1, FinanceFormulas::getRateOfInflation(500, 1000));
 
         self::assertEquals(1000 / 500, FinanceFormulas::getPaybackPeriod(1000, 500));
         self::assertEquals(100 / 0.15, FinanceFormulas::getPresentValueOfPerpetuity(100, 0.15));
@@ -336,6 +349,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta($r, FinanceFormulas::getDoublingContinuousCompoundingRate(13.863), 0.01);
     }
 
+    /**
+     * @testdox Calculations for equivalent annual annuity are correct
+     */
     public function testEquivalentAnnualAnnuity() : void
     {
         $npv = 1000;
@@ -347,6 +363,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta($npv, FinanceFormulas::getNetPresentValueOfEAA(240.36, $r, $n), 0.01);
     }
 
+    /**
+     * @testdox The free cash flow to equity calculation is correct (how much cash is available after expenses and dept payments)
+     */
     public function testFreeCashFlowToEquity() : void
     {
         $income    = 1000;
@@ -358,6 +377,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(1200, FinanceFormulas::getFreeCashFlowToEquity($income, $depamo, $capital, $wc, $borrowing), 0.01);
     }
 
+    /**
+     * @testdox The free cash flow to firm calculation is correct (how much cash is available after expenses)
+     */
     public function testFreeCashFlowToFirm() : void
     {
         $ebit    = 1000;
@@ -369,6 +391,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(550, FinanceFormulas::getFreeCashFlowToFirm($ebit, $t, $depamo, $capital, $wc), 0.01);
     }
 
+    /**
+     * @testdox The future value calculation is correct
+     */
     public function testFutureValue() : void
     {
         $c = 1000;
@@ -378,6 +403,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(2660.02, FinanceFormulas::getFutureValue($c, $r, $n), 0.01);
     }
 
+    /**
+     * @testdox The future value calculation including continuous compounding is correct
+     */
     public function testFutureValueContinuousCompounding() : void
     {
         $pv = 1000;
@@ -387,6 +415,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(2857.65, FinanceFormulas::getFutureValueContinuousCompounding($pv, $r, $t), 0.01);
     }
 
+    /**
+     * @testdox The future value factor calculation is correct
+     */
     public function testValueFactor() : void
     {
         $r = 0.15;
@@ -396,6 +427,9 @@ class FinanceFormulasTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(0.37594, FinanceFormulas::getPresentValueFactor($r, $n), 0.01);
     }
 
+    /**
+     * @testdox The calculation of the geometric mean of multiple return rates is correct
+     */
     public function testGeometricMeanReturn() : void
     {
         $r = [0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07];
diff --git a/tests/Business/Finance/LoanTest.php b/tests/Business/Finance/LoanTest.php
index 70a0b4a78..c0b5e468d 100644
--- a/tests/Business/Finance/LoanTest.php
+++ b/tests/Business/Finance/LoanTest.php
@@ -17,16 +17,31 @@ namespace phpOMS\tests\Business\Finance;
 use phpOMS\Business\Finance\Loan;
 
 /**
+ * @testdox phpOMS\tests\Business\Finance\LoanTest: Loan formulas
+ *
  * @internal
  */
 class LoanTest extends \PHPUnit\Framework\TestCase
 {
-    public function testRatios() : void
+    /**
+     * @testdox The loan to deposit ratio is correct
+     */
+    public function testLoanToDepositRatio() : void
     {
         self::assertEquals(100 / 50, Loan::getLoanToDepositRatio(100, 50));
+    }
+
+    /**
+     * @testdox The loan to value ratio is correct
+     */
+    public function testLoanToValueRatio() : void
+    {
         self::assertEquals(100 / 50, Loan::getLoanToValueRatio(100, 50));
     }
 
+    /**
+     * @testdox The balloon loan payments are correct for a given balloon
+     */
     public function testPaymentsOnBalloonLoan() : void
     {
         $pv      = 1000;
@@ -37,6 +52,9 @@ class LoanTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(213.25, Loan::getPaymentsOnBalloonLoan($pv, $r, $n, $balloon), 0.01);
     }
 
+    /**
+     * @testdox The balloon loan residual value (balloon) is correct for given payments
+     */
     public function testBalloonBalanceOfLoan() : void
     {
         $pv = 1000;
@@ -47,6 +65,9 @@ class LoanTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(-660.02, Loan::getBalloonBalanceOfLoan($pv, $p, $r, $n), 0.01);
     }
 
+    /**
+     * @testdox The loan payments are correct for a given interest rate and period [continuous compounding]
+     */
     public function testLoanPayment() : void
     {
         $pv = 1000;
@@ -56,6 +77,9 @@ class LoanTest extends \PHPUnit\Framework\TestCase
         self::assertEqualsWithDelta(240.36, Loan::getLoanPayment($pv, $r, $n), 0.01);
     }
 
+    /**
+     * @testdox The residual value is correct for a given payment amount, interest rate and period [continuous compounding]
+     */
     public function testRemainingBalanceLoan() : void
     {
         $pv = 1000;
diff --git a/tests/Business/Finance/LorenzkurveTest.php b/tests/Business/Finance/LorenzkurveTest.php
index 506ae3af3..c70aec983 100644
--- a/tests/Business/Finance/LorenzkurveTest.php
+++ b/tests/Business/Finance/LorenzkurveTest.php
@@ -17,14 +17,19 @@ namespace phpOMS\tests\Business\Finance;
 use phpOMS\Business\Finance\Lorenzkurve;
 
 /**
+ * @testdox phpOMS\tests\Business\Finance\LorenzkurveTest: Lorenz kurve
+ *
  * @internal
  */
 class LorenzkurveTest extends \PHPUnit\Framework\TestCase
 {
-    public function testLorenz() : void
+    /**
+     * @testdox The gini coefficient calculation is correct
+     */
+    public function testGiniCoefficient() : void
     {
         $arr = [1, 1, 1, 1, 1, 1, 1, 10, 33, 50];
 
-        self::assertTrue(\abs(0.71 - LorenzKurve::getGiniCoefficient($arr)) < 0.01);
+        self::assertEqualsWithDelta(0.71, LorenzKurve::getGiniCoefficient($arr), 0.01);
     }
 }
diff --git a/tests/Business/Marketing/MetricsTest.php b/tests/Business/Marketing/MetricsTest.php
index 88cb1e8e1..ddbe9087b 100644
--- a/tests/Business/Marketing/MetricsTest.php
+++ b/tests/Business/Marketing/MetricsTest.php
@@ -28,6 +28,6 @@ class MetricsTest extends \PHPUnit\Framework\TestCase
      */
     public function testCustomerRetention() : void
     {
-        self::assertTrue(0.85 - Metrics::getCustomerRetention(105, 20, 100) < 0.01);
+        self::assertEqualsWithDelta(0.85, Metrics::getCustomerRetention(105, 20, 100), 0.01);
     }
 }
diff --git a/tests/Business/Marketing/NetPromoterScoreTest.php b/tests/Business/Marketing/NetPromoterScoreTest.php
index 35ccceab1..badf16840 100644
--- a/tests/Business/Marketing/NetPromoterScoreTest.php
+++ b/tests/Business/Marketing/NetPromoterScoreTest.php
@@ -24,7 +24,7 @@ use phpOMS\Business\Marketing\NetPromoterScore;
 class NetPromoterScoreTest extends \PHPUnit\Framework\TestCase
 {
     /**
-     * @testdox The default net promoter score is 0
+     * @testdox The net promoter has the expected default values after initialization
      */
     public function testDefault() : void
     {
diff --git a/tests/Business/Sales/MarketShareEstimationTest.php b/tests/Business/Sales/MarketShareEstimationTest.php
index db23a1ade..e5667856d 100644
--- a/tests/Business/Sales/MarketShareEstimationTest.php
+++ b/tests/Business/Sales/MarketShareEstimationTest.php
@@ -17,6 +17,7 @@ use phpOMS\Business\Sales\MarketShareEstimation;
 
 /**
  * @testdox phpOMS\tests\Business\Sales\MarketShareEstimationTest: Market share calculations
+ *
  * @internal
  */
 class MarketShareEstimationTest extends \PHPUnit\Framework\TestCase
diff --git a/tests/Config/OptionsTraitTest.php b/tests/Config/OptionsTraitTest.php
index b8565d6cd..466dad93b 100644
--- a/tests/Config/OptionsTraitTest.php
+++ b/tests/Config/OptionsTraitTest.php
@@ -19,12 +19,17 @@ use phpOMS\Config\OptionsTrait;
 require_once __DIR__ . '/../Autoloader.php';
 
 /**
+ * @testdox phpOMS\tests\Config\OptionsTrait: Helper for managing otpions
+ *
  * @internal
  */
 class OptionsTraitTest extends \PHPUnit\Framework\TestCase
 {
 
-    public function testOptionTrait() : void
+    /**
+     * @testdox The option helper has the expected attributes
+     */
+    public function testOptionTraitMembers() : void
     {
         $class = new class() {
             use OptionsTrait;
@@ -34,6 +39,9 @@ class OptionsTraitTest extends \PHPUnit\Framework\TestCase
         self::assertObjectHasAttribute('options', $class);
     }
 
+    /**
+     * @testdox The option helper has the expected default values after initialization
+     */
     public function testDefault() : void
     {
         $class = new class() {
@@ -44,7 +52,24 @@ class OptionsTraitTest extends \PHPUnit\Framework\TestCase
         self::assertNull($class->getOption('someKey'));
     }
 
-    public function testSetGet() : void
+    /**
+     * @testdox Options can be added to the helper
+     */
+    public function testAdd() : void
+    {
+        $class = new class() {
+            use OptionsTrait;
+        };
+
+        self::assertTrue($class->setOption('a', 'value1'));
+        self::assertTrue($class->exists('a'));
+        self::assertEquals('value1', $class->getOption('a'));
+    }
+
+    /**
+     * @testdox Options can be overwritten/changed
+     */
+    public function testOverwrite() : void
     {
         $class = new class() {
             use OptionsTrait;
@@ -65,12 +90,27 @@ class OptionsTraitTest extends \PHPUnit\Framework\TestCase
         self::assertFalse($class->setOption('a', 'value4', false));
         self::assertTrue($class->exists('a'));
         self::assertEquals('value3', $class->getOption('a'));
+    }
+
+    /**
+     * @testdox Multiple options can be added to the helper in one go
+     */
+    public function testAddMultiple() : void
+    {
+        $class = new class() {
+            use OptionsTrait;
+        };
+
+        self::assertTrue($class->setOption('a', 'value3', true));
+        self::assertTrue($class->exists('a'));
+        self::assertEquals('value3', $class->getOption('a'));
 
         self::assertTrue($class->setOptions(['b' => 2, 'c' => '3'], true));
         self::assertTrue($class->setOptions(['b' => 4, 'c' => '5'], false)); // always returns true
         self::assertTrue($class->exists('a'));
         self::assertTrue($class->exists('b'));
         self::assertTrue($class->exists('c'));
+
         self::assertEquals('value3', $class->getOption('a'));
         self::assertEquals(2, $class->getOption('b'));
         self::assertEquals(3, $class->getOption('c'));
diff --git a/tests/DataStorage/Cache/CachePoolTest.php b/tests/DataStorage/Cache/CachePoolTest.php
index 66675a63a..1ef50fc0a 100644
--- a/tests/DataStorage/Cache/CachePoolTest.php
+++ b/tests/DataStorage/Cache/CachePoolTest.php
@@ -18,10 +18,15 @@ use phpOMS\DataStorage\Cache\CachePool;
 use phpOMS\DataStorage\Cache\Connection\FileCache;
 
 /**
+ * @testdox phpOMS\tests\DataStorage\Cache\CachePoolTest: Pool for caches
+ *
  * @internal
  */
 class CachePoolTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The pool has the expected default values after initialization
+     */
     public function testDefault() : void
     {
         $pool = new CachePool();
@@ -30,20 +35,84 @@ class CachePoolTest extends \PHPUnit\Framework\TestCase
         self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\NullCache', $pool->get());
     }
 
-    public function testGetSet() : void
+    /**
+     * @testdox New cache connections can be added to the pool
+     */
+    public function testAdd() : void
+    {
+        $pool = new CachePool();
+
+        self::assertTrue($pool->add('test', new FileCache(__DIR__)));
+    }
+
+    /**
+     * @testdox Cache connections cannot be overwritten with a different cache connection
+     */
+    public function testOverwrite() : void
     {
         $pool = new CachePool();
 
         self::assertTrue($pool->add('test', new FileCache(__DIR__)));
         self::assertFalse($pool->add('test', new FileCache(__DIR__)));
+    }
+
+    /**
+     * @testdox Cache connections can be accessed with an identifier
+     */
+    public function testGet() : void
+    {
+        $pool = new CachePool();
+
+        self::assertTrue($pool->add('test', new FileCache(__DIR__)));
         self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\ConnectionInterface', $pool->get('test'));
         self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\ConnectionInterface', $pool->get());
+    }
+
+    /**
+     * @testdox By default a null cache is returned if no cache connection exists for the identifier
+     */
+    public function testGetDefault() : void
+    {
+        $pool = new CachePool();
+
+        self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\NullCache', $pool->get('abc'));
+    }
+
+    /**
+     * @testdox Cache connections can created by the pool and automatically get added but not overwritten
+     */
+    public function testCreate() : void
+    {
+        $pool = new CachePool();
+
         self::assertTrue($pool->create('abc', ['type' => 'file', 'path' => __DIR__]));
         self::assertFalse($pool->create('abc', ['type' => 'file', 'path' => __DIR__]));
         self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\ConnectionInterface', $pool->get('abc'));
+    }
+
+    /**
+     * @testdox Cache connections can be removed from the pool
+     */
+    public function testRemove() : void
+    {
+        $pool = new CachePool();
+
+        self::assertTrue($pool->add('test', new FileCache(__DIR__)));
+        self::assertTrue($pool->create('abc', ['type' => 'file', 'path' => __DIR__]));
         self::assertTrue($pool->remove('abc'));
         self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\NullCache', $pool->get('abc'));
         self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\ConnectionInterface', $pool->get('test'));
+    }
+
+    /**
+     * @testdox Removing a cache with an invalid identifier will result in no actions
+     */
+    public function testRemoveInvalid() : void
+    {
+        $pool = new CachePool();
+
+        self::assertTrue($pool->add('test', new FileCache(__DIR__)));
         self::assertFalse($pool->remove('abc'));
+        self::assertInstanceOf('\phpOMS\DataStorage\Cache\Connection\ConnectionInterface', $pool->get('test'));
     }
 }
diff --git a/tests/DataStorage/Cache/Connection/ConnectionFactoryTest.php b/tests/DataStorage/Cache/Connection/ConnectionFactoryTest.php
index 390373f1c..dbebb3d13 100644
--- a/tests/DataStorage/Cache/Connection/ConnectionFactoryTest.php
+++ b/tests/DataStorage/Cache/Connection/ConnectionFactoryTest.php
@@ -18,10 +18,15 @@ use phpOMS\DataStorage\Cache\CacheType;
 use phpOMS\DataStorage\Cache\Connection\ConnectionFactory;
 
 /**
+ * @testdox phpOMS\tests\DataStorage\Cache\Connection\ConnectionFactoryTest: Factory for generating cache connections
+ *
  * @internal
  */
 class ConnectionFactoryTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The file cache can be created
+     */
     public function testCreateFileCache() : void
     {
         self::assertInstanceOf(
@@ -30,6 +35,9 @@ class ConnectionFactoryTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox The memcached cache can be created
+     */
     public function testCreateMemCached() : void
     {
         if (!\extension_loaded('memcached')) {
@@ -44,6 +52,9 @@ class ConnectionFactoryTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox The redis cache can be created
+     */
     public function testCreateRedisCache() : void
     {
         if (!\extension_loaded('redis')) {
@@ -58,6 +69,9 @@ class ConnectionFactoryTest extends \PHPUnit\Framework\TestCase
         );
     }
 
+    /**
+     * @testdox An invalid cache type results in an exception
+     */
     public function testInvalidCacheType() : void
     {
         self::expectException(\InvalidArgumentException::class);
diff --git a/tests/DataStorage/Cache/Connection/FileCacheTest.php b/tests/DataStorage/Cache/Connection/FileCacheTest.php
index 41ba53391..ab8b20800 100644
--- a/tests/DataStorage/Cache/Connection/FileCacheTest.php
+++ b/tests/DataStorage/Cache/Connection/FileCacheTest.php
@@ -20,10 +20,15 @@ use phpOMS\DataStorage\Cache\Connection\FileCache;
 use phpOMS\Utils\TestUtils;
 
 /**
+ * @testdox phpOMS\tests\DataStorage\Cache\Connection\FileCacheTest: File cache connection
+ *
  * @internal
  */
 class FileCacheTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @testdox The file cache connection has the expected default values after initialization
+     */
     public function testDefault() : void
     {
         if (\file_exists(__DIR__ . '/Cache')) {
@@ -44,6 +49,9 @@ class FileCacheTest extends \PHPUnit\Framework\TestCase
         }
     }
 
+    /**
+     * @testdox The connection to a dedicated cache directory can be established (none-exising directories get created)
+     */
     public function testConnect() : void
     {
         if (\file_exists(__DIR__ . '/Cache')) {