diff --git a/src/PhpSpreadsheet/Calculation/Statistical.php b/src/PhpSpreadsheet/Calculation/Statistical.php
index 1df2cb1f..43cea81e 100644
--- a/src/PhpSpreadsheet/Calculation/Statistical.php
+++ b/src/PhpSpreadsheet/Calculation/Statistical.php
@@ -2,8 +2,6 @@
 
 namespace PHPExcel\Calculation;
 
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/trendClass.php';
-
 
 /** LOG_GAMMA_X_MAX_VALUE */
 define('LOG_GAMMA_X_MAX_VALUE', 2.55e305);
@@ -1168,7 +1166,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getCorrelation();
     }
 
@@ -1326,7 +1324,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getCovariance();
     }
 
@@ -1612,7 +1610,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getValueOfYForX($xValue);
     }
 
@@ -1783,7 +1781,7 @@ class Statistical
         $newValues = Functions::flattenArray($newValues);
         $const = (is_null($const)) ? true : (boolean) Functions::flattenSingleValue($const);
 
-        $bestFitExponential = trendClass::calculate(trendClass::TREND_EXPONENTIAL, $yValues, $xValues, $const);
+        $bestFitExponential = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_EXPONENTIAL, $yValues, $xValues, $const);
         if (empty($newValues)) {
             $newValues = $bestFitExponential->getXValues();
         }
@@ -1907,7 +1905,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getIntersect();
     }
 
@@ -2029,7 +2027,7 @@ class Statistical
             return 0;
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues, $const);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues, $const);
         if ($stats) {
             return array(
                 array(
@@ -2095,7 +2093,7 @@ class Statistical
             return 1;
         }
 
-        $bestFitExponential = trendClass::calculate(trendClass::TREND_EXPONENTIAL, $yValues, $xValues, $const);
+        $bestFitExponential = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_EXPONENTIAL, $yValues, $xValues, $const);
         if ($stats) {
             return array(
                 array(
@@ -2920,7 +2918,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getGoodnessOfFit();
     }
 
@@ -2986,7 +2984,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getSlope();
     }
 
@@ -3279,7 +3277,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
         return $bestFitLinear->getStdevOfResiduals();
     }
 
@@ -3422,7 +3420,7 @@ class Statistical
         $newValues = Functions::flattenArray($newValues);
         $const = (is_null($const)) ? true : (boolean) Functions::flattenSingleValue($const);
 
-        $bestFitLinear = trendClass::calculate(trendClass::TREND_LINEAR, $yValues, $xValues, $const);
+        $bestFitLinear = \PHPExcel\Shared\trend\trend::calculate(\PHPExcel\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues, $const);
         if (empty($newValues)) {
             $newValues = $bestFitLinear->getXValues();
         }
diff --git a/src/PhpSpreadsheet/Calculation/TextData.php b/src/PhpSpreadsheet/Calculation/TextData.php
index 9e29391b..b4f68801 100644
--- a/src/PhpSpreadsheet/Calculation/TextData.php
+++ b/src/PhpSpreadsheet/Calculation/TextData.php
@@ -502,7 +502,7 @@ class TextData
      * @param    string    $newText    String to replace in defined position
      * @return    string
      */
-    public static function REPLACE($oldText = '', $start = 1, $chars = null, $newText)
+    public static function REPLACE($oldText, $start, $chars, $newText)
     {
         $oldText = Functions::flattenSingleValue($oldText);
         $start   = Functions::flattenSingleValue($start);
diff --git a/src/PhpSpreadsheet/Reader/Excel2003XML.php b/src/PhpSpreadsheet/Reader/Excel2003XML.php
index 5a1c0a21..733336f5 100644
--- a/src/PhpSpreadsheet/Reader/Excel2003XML.php
+++ b/src/PhpSpreadsheet/Reader/Excel2003XML.php
@@ -1,7 +1,6 @@
 <?php
 
 namespace PHPExcel\Reader;
-use PHPExcel\Shared\TimeZone;
 
 /**
  * PHPExcel_Reader_Excel2003XML
diff --git a/src/PhpSpreadsheet/Reader/OOCalc.php b/src/PhpSpreadsheet/Reader/OOCalc.php
index 81a827d1..c99718e1 100644
--- a/src/PhpSpreadsheet/Reader/OOCalc.php
+++ b/src/PhpSpreadsheet/Reader/OOCalc.php
@@ -473,10 +473,11 @@ class OOCalc extends BaseReader implements IReader
 //                    echo '<b>'.$key.'</b><br />';
                     switch ($key) {
                         case 'table-header-rows':
-                            foreach ($rowData as $key => $cellData) {
+                            foreach ($rowData as $keyRowData => $cellData) {
                                 $rowData = $cellData;
                                 break;
                             }
+                            break;
                         case 'table-row':
                             $rowDataTableAttributes = $rowData->attributes($namespacesContent['table']);
                             $rowRepeats = (isset($rowDataTableAttributes['number-rows-repeated'])) ? $rowDataTableAttributes['number-rows-repeated'] : 1;
diff --git a/src/PhpSpreadsheet/Shared/Drawing.php b/src/PhpSpreadsheet/Shared/Drawing.php
index 4f94ec4b..5d59211b 100644
--- a/src/PhpSpreadsheet/Shared/Drawing.php
+++ b/src/PhpSpreadsheet/Shared/Drawing.php
@@ -64,7 +64,7 @@ class Drawing
      * @param    \PHPExcel\Style\Font $pDefaultFont    Default font of the workbook
      * @return   int            Value in cell dimension
      */
-    public static function pixelsToCellDimension($pValue = 0, \PHPExcel\Style\Font $pDefaultFont)
+    public static function pixelsToCellDimension($pValue, \PHPExcel\Style\Font $pDefaultFont)
     {
         // Font name and size
         $name = $pDefaultFont->getName();
@@ -89,7 +89,7 @@ class Drawing
      * @param   \PHPExcel\Style\Font $pDefaultFont    Default font of the workbook
      * @return  int        Value in pixels
      */
-    public static function cellDimensionToPixels($pValue = 0, \PHPExcel\Style\Font $pDefaultFont)
+    public static function cellDimensionToPixels($pValue, \PHPExcel\Style\Font $pDefaultFont)
     {
         // Font name and size
         $name = $pDefaultFont->getName();
diff --git a/src/PhpSpreadsheet/Shared/JAMA/Matrix.php b/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
index 9158de25..77b48d83 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
@@ -1088,6 +1088,7 @@ class Matrix
                     } else {
                         throw new \PHPExcel\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
                     }
+                    break;
                 case 'array':
                     $M = new Matrix($args[0]);
                     break;
diff --git a/src/PhpSpreadsheet/Shared/trend/bestFitClass.php b/src/PhpSpreadsheet/Shared/trend/bestFit.php
similarity index 99%
rename from src/PhpSpreadsheet/Shared/trend/bestFitClass.php
rename to src/PhpSpreadsheet/Shared/trend/bestFit.php
index 2de029f9..afff9a8d 100644
--- a/src/PhpSpreadsheet/Shared/trend/bestFitClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/bestFit.php
@@ -1,7 +1,9 @@
 <?php
 
+namespace PHPExcel\Shared\trend;
+
 /**
- * PHPExcel_Best_Fit
+ * bestFit
  *
  * Copyright (c) 2006 - 2015 PHPExcel
  *
@@ -25,7 +27,7 @@
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class PHPExcel_Best_Fit
+class bestFit
 {
     /**
      * Indicator flag for a calculation error
diff --git a/src/PhpSpreadsheet/Shared/trend/exponentialBestFitClass.php b/src/PhpSpreadsheet/Shared/trend/exponentialBestFit.php
similarity index 97%
rename from src/PhpSpreadsheet/Shared/trend/exponentialBestFitClass.php
rename to src/PhpSpreadsheet/Shared/trend/exponentialBestFit.php
index 44487352..b3a5117b 100644
--- a/src/PhpSpreadsheet/Shared/trend/exponentialBestFitClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/exponentialBestFit.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php');
+namespace PHPExcel\Shared\trend;
 
 /**
  * PHPExcel_Exponential_Best_Fit
@@ -27,7 +27,7 @@ require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php');
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class PHPExcel_Exponential_Best_Fit extends PHPExcel_Best_Fit
+class exponentialBestFit extends bestFit
 {
     /**
      * Algorithm type to use for best-fit
diff --git a/src/PhpSpreadsheet/Shared/trend/linearBestFitClass.php b/src/PhpSpreadsheet/Shared/trend/linearBestFit.php
similarity index 96%
rename from src/PhpSpreadsheet/Shared/trend/linearBestFitClass.php
rename to src/PhpSpreadsheet/Shared/trend/linearBestFit.php
index 76b55b3e..20ab8abf 100644
--- a/src/PhpSpreadsheet/Shared/trend/linearBestFitClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/linearBestFit.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php');
+namespace PHPExcel\Shared\trend;
 
 /**
  * PHPExcel_Linear_Best_Fit
@@ -27,7 +27,7 @@ require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php');
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class PHPExcel_Linear_Best_Fit extends PHPExcel_Best_Fit
+class linearBestFit extends bestFit
 {
     /**
      * Algorithm type to use for best-fit
diff --git a/src/PhpSpreadsheet/Shared/trend/logarithmicBestFitClass.php b/src/PhpSpreadsheet/Shared/trend/logarithmicBestFit.php
similarity index 96%
rename from src/PhpSpreadsheet/Shared/trend/logarithmicBestFitClass.php
rename to src/PhpSpreadsheet/Shared/trend/logarithmicBestFit.php
index 221c5386..028517c2 100644
--- a/src/PhpSpreadsheet/Shared/trend/logarithmicBestFitClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/logarithmicBestFit.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php');
+namespace PHPExcel\Shared\trend;
 
 /**
  * PHPExcel_Logarithmic_Best_Fit
@@ -27,7 +27,7 @@ require_once(PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php');
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class PHPExcel_Logarithmic_Best_Fit extends PHPExcel_Best_Fit
+class logarithmicBestFit extends bestFit
 {
     /**
      * Algorithm type to use for best-fit
diff --git a/src/PhpSpreadsheet/Shared/trend/polynomialBestFitClass.php b/src/PhpSpreadsheet/Shared/trend/polynomialBestFit.php
similarity index 97%
rename from src/PhpSpreadsheet/Shared/trend/polynomialBestFitClass.php
rename to src/PhpSpreadsheet/Shared/trend/polynomialBestFit.php
index 8a882b74..b439d355 100644
--- a/src/PhpSpreadsheet/Shared/trend/polynomialBestFitClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/polynomialBestFit.php
@@ -1,7 +1,6 @@
 <?php
 
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php';
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/JAMA/Matrix.php';
+namespace PHPExcel\Shared\trend;
 
 /**
  * PHPExcel_Polynomial_Best_Fit
@@ -28,7 +27,7 @@ require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/JAMA/Matrix.php';
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class PHPExcel_Polynomial_Best_Fit extends PHPExcel_Best_Fit
+class polynomialBestFit extends bestFit
 {
     /**
      * Algorithm type to use for best-fit
diff --git a/src/PhpSpreadsheet/Shared/trend/powerBestFitClass.php b/src/PhpSpreadsheet/Shared/trend/powerBestFit.php
similarity index 96%
rename from src/PhpSpreadsheet/Shared/trend/powerBestFitClass.php
rename to src/PhpSpreadsheet/Shared/trend/powerBestFit.php
index 77c47342..c395466c 100644
--- a/src/PhpSpreadsheet/Shared/trend/powerBestFitClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/powerBestFit.php
@@ -1,9 +1,9 @@
 <?php
 
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php';
+namespace PHPExcel\Shared\trend;
 
 /**
- * PHPExcel_Power_Best_Fit
+ * \PHPExcel\Shared\trend\powerBestFit
  *
  * Copyright (c) 2006 - 2015 PHPExcel
  *
@@ -27,7 +27,7 @@ require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php';
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class PHPExcel_Power_Best_Fit extends PHPExcel_Best_Fit
+class powerBestFit extends bestFit
 {
     /**
      * Algorithm type to use for best-fit
diff --git a/src/PhpSpreadsheet/Shared/trend/trendClass.php b/src/PhpSpreadsheet/Shared/trend/trend.php
similarity index 86%
rename from src/PhpSpreadsheet/Shared/trend/trendClass.php
rename to src/PhpSpreadsheet/Shared/trend/trend.php
index 715cd412..8979bf62 100644
--- a/src/PhpSpreadsheet/Shared/trend/trendClass.php
+++ b/src/PhpSpreadsheet/Shared/trend/trend.php
@@ -1,13 +1,9 @@
 <?php
 
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/linearBestFitClass.php';
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/logarithmicBestFitClass.php';
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/exponentialBestFitClass.php';
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/powerBestFitClass.php';
-require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/polynomialBestFitClass.php';
+namespace PHPExcel\Shared\trend;
 
 /**
- * PHPExcel_trendClass
+ * PHPExcel_\PHPExcel\Shared\trend\trend
  *
  * Copyright (c) 2006 - 2015 PHPExcel
  *
@@ -31,7 +27,7 @@ require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/polynomialBestFitClass.php';
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  * @version    ##VERSION##, ##DATE##
  */
-class trendClass
+class trend
 {
     const TREND_LINEAR            = 'Linear';
     const TREND_LOGARITHMIC       = 'Logarithmic';
@@ -73,7 +69,7 @@ class trendClass
     /**
      * Cached results for each method when trying to identify which provides the best fit
      *
-     * @var PHPExcel_Best_Fit[]
+     * @var bestFit[]
      **/
     private static $trendCache = array();
 
@@ -102,7 +98,7 @@ class trendClass
             case self::TREND_EXPONENTIAL:
             case self::TREND_POWER:
                 if (!isset(self::$trendCache[$key])) {
-                    $className = 'PHPExcel_'.$trendType.'_Best_Fit';
+                    $className = '\PHPExcel\Shared\trend\\'.strtolower($trendType).'BestFit';
                     self::$trendCache[$key] = new $className($yValues, $xValues, $const);
                 }
                 return self::$trendCache[$key];
@@ -113,7 +109,7 @@ class trendClass
             case self::TREND_POLYNOMIAL_6:
                 if (!isset(self::$trendCache[$key])) {
                     $order = substr($trendType, -1);
-                    self::$trendCache[$key] = new PHPExcel_Polynomial_Best_Fit($order, $yValues, $xValues, $const);
+                    self::$trendCache[$key] = new polynomialBestFit($order, $yValues, $xValues, $const);
                 }
                 return self::$trendCache[$key];
             case self::TREND_BEST_FIT:
@@ -121,14 +117,14 @@ class trendClass
                 //    If the request is to determine the best fit regression, then we test each trend line in turn
                 //    Start by generating an instance of each available trend method
                 foreach (self::$trendTypes as $trendMethod) {
-                    $className = 'PHPExcel_'.$trendMethod.'BestFit';
+                    $className = '\PHPExcel\Shared\trend\\'.strtolower($trendType).'BestFit';
                     $bestFit[$trendMethod] = new $className($yValues, $xValues, $const);
                     $bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
                 }
                 if ($trendType != self::TREND_BEST_FIT_NO_POLY) {
                     foreach (self::$trendTypePolynomialOrders as $trendMethod) {
                         $order = substr($trendMethod, -1);
-                        $bestFit[$trendMethod] = new PHPExcel_Polynomial_Best_Fit($order, $yValues, $xValues, $const);
+                        $bestFit[$trendMethod] = new polynomialBestFit($order, $yValues, $xValues, $const);
                         if ($bestFit[$trendMethod]->getError()) {
                             unset($bestFit[$trendMethod]);
                         } else {
diff --git a/src/PhpSpreadsheet/Writer/Excel2007/Chart.php b/src/PhpSpreadsheet/Writer/Excel2007/Chart.php
index 507f46b7..b8dfe063 100644
--- a/src/PhpSpreadsheet/Writer/Excel2007/Chart.php
+++ b/src/PhpSpreadsheet/Writer/Excel2007/Chart.php
@@ -126,7 +126,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeTitle(Title $title = null, $objWriter)
+    private function writeTitle(Title $title, $objWriter)
     {
         if (is_null($title)) {
             return;
@@ -171,7 +171,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeLegend(Legend $legend = null, $objWriter)
+    private function writeLegend(Legend $legend, $objWriter)
     {
         if (is_null($legend)) {
             return;
@@ -226,7 +226,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writePlotArea(PlotArea $plotArea, Title $xAxisLabel = null, Title $yAxisLabel = null, $objWriter, \PHPExcel\Worksheet $pSheet, Axis $xAxis, Axis $yAxis, GridLines $majorGridlines, GridLines $minorGridlines)
+    private function writePlotArea(PlotArea $plotArea, Title $xAxisLabel, Title $yAxisLabel, $objWriter, \PHPExcel\Worksheet $pSheet, Axis $xAxis, Axis $yAxis, GridLines $majorGridlines, GridLines $minorGridlines)
     {
         if (is_null($plotArea)) {
             return;
@@ -270,7 +270,6 @@ class Chart extends WriterPart
 
             if ($chartType === DataSeries::TYPE_LINECHART) {
                 //    Line only, Line3D can't be smoothed
-
                 $objWriter->startElement('c:smooth');
                 $objWriter->writeAttribute('val', (integer) $plotGroup->getSmoothLine());
                 $objWriter->endElement();
@@ -1404,7 +1403,7 @@ class Chart extends WriterPart
      *
      * @throws  \PHPExcel\Writer\Exception
      */
-    private function writeLayout(Layout $layout = null, $objWriter)
+    private function writeLayout(Layout $layout, $objWriter)
     {
         $objWriter->startElement('c:layout');
 
diff --git a/src/PhpSpreadsheet/Writer/Excel2007/Drawing.php b/src/PhpSpreadsheet/Writer/Excel2007/Drawing.php
index 0573b46b..ca04da2f 100644
--- a/src/PhpSpreadsheet/Writer/Excel2007/Drawing.php
+++ b/src/PhpSpreadsheet/Writer/Excel2007/Drawing.php
@@ -1,5 +1,6 @@
 <?php
 namespace PHPExcel\Writer\Excel2007;
+
 use PHPExcel\Chart;
 
 /**
@@ -38,7 +39,7 @@ class Drawing extends WriterPart
      * @return string          XML Output
      * @throws     \PHPExcel\Writer\Exception
      */
-    public function writeDrawings(\PHPExcel\Worksheet $pWorksheet = null, &$chartRef, $includeCharts = false)
+    public function writeDrawings(\PHPExcel\Worksheet $pWorksheet, &$chartRef, $includeCharts = false)
     {
         // Create XML writer
         $objWriter = null;
diff --git a/src/PhpSpreadsheet/Writer/Excel2007/Rels.php b/src/PhpSpreadsheet/Writer/Excel2007/Rels.php
index 57332bc0..c520ca73 100644
--- a/src/PhpSpreadsheet/Writer/Excel2007/Rels.php
+++ b/src/PhpSpreadsheet/Writer/Excel2007/Rels.php
@@ -298,7 +298,7 @@ class Rels extends WriterPart
      * @return string          XML Output
      * @throws     \PHPExcel\Writer\Exception
      */
-    public function writeDrawingRelationships(\PHPExcel\Worksheet $pWorksheet = null, &$chartRef, $includeCharts = false)
+    public function writeDrawingRelationships(\PHPExcel\Worksheet $pWorksheet, &$chartRef, $includeCharts = false)
     {
         // Create XML writer
         $objWriter = null;
diff --git a/src/PhpSpreadsheet/Writer/Excel5/Workbook.php b/src/PhpSpreadsheet/Writer/Excel5/Workbook.php
index 1adddfe0..fa9832ca 100644
--- a/src/PhpSpreadsheet/Writer/Excel5/Workbook.php
+++ b/src/PhpSpreadsheet/Writer/Excel5/Workbook.php
@@ -187,14 +187,14 @@ class Workbook extends BIFFwriter
     /**
      * Class constructor
      *
-     * @param PHPExcel    $phpExcel        The Workbook
+     * @param \PHPExcel\Spreadsheet $phpExcel The Workbook
      * @param int        &$str_total        Total number of strings
      * @param int        &$str_unique    Total number of unique strings
      * @param array        &$str_table        String Table
      * @param array        &$colors        Colour Table
      * @param mixed        $parser            The formula parser created for the Workbook
      */
-    public function __construct(\PHPExcel\Spreadsheet $phpExcel = null, &$str_total, &$str_unique, &$str_table, &$colors, $parser)
+    public function __construct(\PHPExcel\Spreadsheet $phpExcel, &$str_total, &$str_unique, &$str_table, &$colors, $parser)
     {
         // It needs to call its parent's constructor explicitly
         parent::__construct();
@@ -832,7 +832,7 @@ class Workbook extends BIFFwriter
      * @param    boolean      $isHidden
      * @return    string    Complete binary record data
      * */
-    private function writeShortNameBiff8($name, $sheetIndex = 0, $rangeBounds, $isHidden = false)
+    private function writeShortNameBiff8($name, $sheetIndex, $rangeBounds, $isHidden = false)
     {
         $record = 0x0018;
 
diff --git a/unitTests/phpunit-cc.xml b/unitTests/phpunit-cc.xml
index c6314ff5..aed7cf60 100644
--- a/unitTests/phpunit-cc.xml
+++ b/unitTests/phpunit-cc.xml
@@ -7,8 +7,10 @@
     convertWarningsToExceptions="true" 
     processIsolation="false" 
     syntaxCheck="true" 
-    verbose="true" 
-    strict="true"
+    verbose="true"
+    reportUselessTests="true"
+    strictCoverage="true"
+    disallowTestOutput="true"
     stopOnError="false"
     stopOnFailure="false"
     stopOnIncomplete="false"
diff --git a/unitTests/phpunit.xml b/unitTests/phpunit.xml
index af201967..ec505436 100644
--- a/unitTests/phpunit.xml
+++ b/unitTests/phpunit.xml
@@ -7,8 +7,10 @@
     convertWarningsToExceptions="true" 
     processIsolation="false" 
     syntaxCheck="true" 
-    verbose="true" 
-    strict="true"
+    verbose="true"
+    reportUselessTests="true"
+    strictCoverage="true"
+    disallowTestOutput="true"
     stopOnError="false"
     stopOnFailure="false"
     stopOnIncomplete="false"