diff --git a/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php b/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php
--- a/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php
+++ b/src/applications/fact/chart/PhabricatorChartStackedAreaDataset.php
@@ -148,9 +148,6 @@
     $wire_labels = array();
     foreach ($functions as $function_key => $function) {
       $label = $function->getFunctionLabel();
-
-      $label->setName(pht('Important Data %s', $function_key));
-
       $wire_labels[] = $label->toWireFormat();
     }
 
diff --git a/src/applications/fact/engine/PhabricatorChartEngine.php b/src/applications/fact/engine/PhabricatorChartEngine.php
--- a/src/applications/fact/engine/PhabricatorChartEngine.php
+++ b/src/applications/fact/engine/PhabricatorChartEngine.php
@@ -4,6 +4,10 @@
   extends Phobject {
 
   private $viewer;
+  private $engineParameters = array();
+
+  const KEY_ENGINE = 'engineKey';
+  const KEY_PARAMETERS = 'engineParameters';
 
   final public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
@@ -14,26 +18,65 @@
     return $this->viewer;
   }
 
+  final protected function setEngineParameter($key, $value) {
+    $this->engineParameters[$key] = $value;
+    return $this;
+  }
+
+  final protected function getEngineParameter($key, $default = null) {
+    return idx($this->engineParameters, $key, $default);
+  }
+
+  final protected function getEngineParameters() {
+    return $this->engineParameters;
+  }
+
+  final public static function newFromChart(PhabricatorFactChart $chart) {
+    $engine_key = $chart->getChartParameter(self::KEY_ENGINE);
+
+    $engine_map = self::getAllChartEngines();
+    if (!isset($engine_map[$engine_key])) {
+      throw new Exception(
+        pht(
+          'Chart uses unknown engine key ("%s") and can not be rendered.',
+          $engine_key));
+    }
+
+    return clone id($engine_map[$engine_key]);
+  }
+
+  final public static function getAllChartEngines() {
+    return id(new PhutilClassMapQuery())
+      ->setAncestorClass(__CLASS__)
+      ->setUniqueMethod('getChartEngineKey')
+      ->execute();
+  }
+
   final public function getChartEngineKey() {
     return $this->getPhobjectClassConstant('CHARTENGINEKEY', 32);
   }
 
-  abstract protected function newChart();
+  final public function buildChart(PhabricatorFactChart $chart) {
+    $map = $chart->getChartParameter(self::KEY_PARAMETERS, array());
+    return $this->newChart($chart, $map);
+  }
+
+  abstract protected function newChart(PhabricatorFactChart $chart, array $map);
 
-  final public function buildChart() {
+  final public function buildChartPanel() {
     $viewer = $this->getViewer();
 
-    $chart = $this->newChart();
+    $parameters = $this->getEngineParameters();
+
+    $chart = id(new PhabricatorFactChart())
+      ->setChartParameter(self::KEY_ENGINE, $this->getChartEngineKey())
+      ->setChartParameter(self::KEY_PARAMETERS, $this->getEngineParameters());
 
     $rendering_engine = id(new PhabricatorChartRenderingEngine())
       ->setViewer($viewer)
       ->setChart($chart);
 
-    return $rendering_engine->getStoredChart();
-  }
-
-  final public function buildChartPanel() {
-    $chart = $this->buildChart();
+    $chart = $rendering_engine->getStoredChart();
 
     $panel_type = id(new PhabricatorDashboardChartPanelType())
       ->getPanelTypeKey();
@@ -45,4 +88,10 @@
     return $chart_panel;
   }
 
+  final protected function newFunction($name /* , ... */) {
+    $argv = func_get_args();
+    return id(new PhabricatorComposeChartFunction())
+      ->setArguments(array($argv));
+  }
+
 }
diff --git a/src/applications/fact/engine/PhabricatorChartRenderingEngine.php b/src/applications/fact/engine/PhabricatorChartRenderingEngine.php
--- a/src/applications/fact/engine/PhabricatorChartRenderingEngine.php
+++ b/src/applications/fact/engine/PhabricatorChartRenderingEngine.php
@@ -113,6 +113,10 @@
     $chart = $this->getStoredChart();
     $chart_key = $chart->getChartKey();
 
+    $chart_engine = PhabricatorChartEngine::newFromChart($chart)
+      ->setViewer($this->getViewer());
+    $chart_engine->buildChart($chart);
+
     $datasets = $chart->getDatasets();
 
     $functions = array();
diff --git a/src/applications/fact/storage/PhabricatorFactChart.php b/src/applications/fact/storage/PhabricatorFactChart.php
--- a/src/applications/fact/storage/PhabricatorFactChart.php
+++ b/src/applications/fact/storage/PhabricatorFactChart.php
@@ -7,7 +7,7 @@
   protected $chartKey;
   protected $chartParameters = array();
 
-  private $datasets;
+  private $datasets = self::ATTACHABLE;
 
   protected function getConfiguration() {
     return array(
@@ -54,35 +54,14 @@
     return parent::save();
   }
 
-  public function setDatasets(array $datasets) {
+  public function attachDatasets(array $datasets) {
     assert_instances_of($datasets, 'PhabricatorChartDataset');
-
-    $dataset_list = array();
-    foreach ($datasets as $dataset) {
-      $dataset_list[] = $dataset->toDictionary();
-    }
-
-    $this->setChartParameter('datasets', $dataset_list);
-    $this->datasets = null;
-
+    $this->datasets = $datasets;
     return $this;
   }
 
   public function getDatasets() {
-    if ($this->datasets === null) {
-      $this->datasets = $this->newDatasets();
-    }
-    return $this->datasets;
-  }
-
-  private function newDatasets() {
-    $datasets = $this->getChartParameter('datasets', array());
-
-    foreach ($datasets as $key => $dataset) {
-      $datasets[$key] = PhabricatorChartDataset::newFromDictionary($dataset);
-    }
-
-    return $datasets;
+    return $this->assertAttached($this->datasets);
   }
 
   public function getURI() {
diff --git a/src/applications/project/chart/PhabricatorProjectBurndownChartEngine.php b/src/applications/project/chart/PhabricatorProjectBurndownChartEngine.php
--- a/src/applications/project/chart/PhabricatorProjectBurndownChartEngine.php
+++ b/src/applications/project/chart/PhabricatorProjectBurndownChartEngine.php
@@ -5,52 +5,89 @@
 
   const CHARTENGINEKEY = 'project.burndown';
 
-  private $projects;
-
   public function setProjects(array $projects) {
     assert_instances_of($projects, 'PhabricatorProject');
-
-    $this->projects = $projects;
-
-    return $this;
+    $project_phids = mpull($projects, 'getPHID');
+    return $this->setEngineParameter('projectPHIDs', $project_phids);
   }
 
-  public function getProjects() {
-    return $this->projects;
-  }
+  protected function newChart(PhabricatorFactChart $chart, array $map) {
+    $viewer = $this->getViewer();
+
+    $map = $map + array(
+      'projectPHIDs' => array(),
+    );
 
-  protected function newChart() {
-    if ($this->projects !== null) {
-      $project_phids = mpull($this->projects, 'getPHID');
+    if ($map['projectPHIDs']) {
+      $projects = id(new PhabricatorProjectQuery())
+        ->setViewer($viewer)
+        ->withPHIDs($map['projectPHIDs'])
+        ->execute();
+      $project_phids = mpull($projects, 'getPHID');
     } else {
-      $project_phids = null;
+      $project_phids = array();
     }
 
-    $argvs = array();
+    $functions = array();
     if ($project_phids) {
       foreach ($project_phids as $project_phid) {
-        $argvs[] = array(
+        $function = $this->newFunction(
           'accumulate',
-          array('fact', 'tasks.open-count.create.project', $project_phid),
-        );
-        $argvs[] = array(
+          array('fact', 'tasks.open-count.create.project', $project_phid));
+
+        $function->getFunctionLabel()
+          ->setName(pht('Tasks Created'))
+          ->setColor('rgba(0, 0, 200, 1)')
+          ->setFillColor('rgba(0, 0, 200, 0.15)');
+
+        $functions[] = $function;
+
+
+        $function = $this->newFunction(
           'accumulate',
-          array('fact', 'tasks.open-count.status.project', $project_phid),
-        );
-        $argvs[] = array(
+          array('fact', 'tasks.open-count.status.project', $project_phid));
+
+        $function->getFunctionLabel()
+          ->setName(pht('Tasks Closed / Reopened'))
+          ->setColor('rgba(200, 0, 200, 1)')
+          ->setFillColor('rgba(200, 0, 200, 0.15)');
+
+        $functions[] = $function;
+
+
+        $function = $this->newFunction(
           'accumulate',
-          array('fact', 'tasks.open-count.assign.project', $project_phid),
-        );
+          array('fact', 'tasks.open-count.assign.project', $project_phid));
+
+        $function->getFunctionLabel()
+          ->setName(pht('Tasks Rescoped'))
+          ->setColor('rgba(0, 200, 200, 1)')
+          ->setFillColor('rgba(0, 200, 200, 0.15)');
+
+        $functions[] = $function;
       }
     } else {
-      $argvs[] = array('accumulate', array('fact', 'tasks.open-count.create'));
-      $argvs[] = array('accumulate', array('fact', 'tasks.open-count.status'));
-    }
+      $function = $this->newFunction(
+        'accumulate',
+        array('fact', 'tasks.open-count.create'));
 
-    $functions = array();
-    foreach ($argvs as $argv) {
-      $functions[] = id(new PhabricatorComposeChartFunction())
-        ->setArguments(array($argv));
+      $function->getFunctionLabel()
+        ->setName(pht('Tasks Created'))
+        ->setColor('rgba(0, 200, 200, 1)')
+        ->setFillColor('rgba(0, 200, 200, 0.15)');
+
+      $functions[] = $function;
+
+      $function = $this->newFunction(
+        'accumulate',
+        array('fact', 'tasks.open-count.status'));
+
+      $function->getFunctionLabel()
+        ->setName(pht('Tasks Closed / Reopened'))
+        ->setColor('rgba(200, 0, 200, 1)')
+        ->setFillColor('rgba(200, 0, 200, 0.15)');
+
+      $functions[] = $function;
     }
 
     $datasets = array();
@@ -58,10 +95,7 @@
     $datasets[] = id(new PhabricatorChartStackedAreaDataset())
       ->setFunctions($functions);
 
-    $chart = id(new PhabricatorFactChart())
-      ->setDatasets($datasets);
-
-    return $chart;
+    $chart->attachDatasets($datasets);
   }
 
 }