diff --git a/src/pert.coffee b/src/PBSlib.coffee
similarity index 96%
rename from src/pert.coffee
rename to src/PBSlib.coffee
index db1f749..fc5b89e 100644
--- a/src/pert.coffee
+++ b/src/PBSlib.coffee
@@ -1,13 +1,13 @@
-class Pert
+class PBS
   constructor: (@list, @verbose) ->
-    @verbose = true
     @days = []
     @criticalPaths = []
 
   log: (x...) ->
-    if chalk?
-      console.log chalk.bold "[ Pert ]", x...
-    else console.log "[ Pert ]", x...
+    if @verbose
+      if chalk?
+        console.log chalk.bold "[ Pert ]", x...
+      else console.log "[ Pert ]", x...
   err: (x...) ->
     if chalk?
       console.log chalk.bold chalk.red("[ !Pert! ]"), x...
diff --git a/src/app.coffee b/src/app.coffee
index 1e9f607..46db041 100644
--- a/src/app.coffee
+++ b/src/app.coffee
@@ -41,10 +41,12 @@ pertController = ($scope) ->
     if !data.push?
       return swal 'Error', 'data is not a list', 'error'
     try
-      console.log "Saving: "+data
-      localStorage.setItem 'ganttpert', JSON.stringify data
+      sdata = JSON.stringify data
+      console.log "Saving: "+sdata
+      localStorage.setItem 'ganttpert', sdata
       unless options.silent
         swal 'Ok', 'Data updated', 'success'
+      $scope.pbs = new PBS(data).calculate()
       $scope.$broadcast 'dataChanged'
     catch e
       swal 'Error', e, 'error'
@@ -69,6 +71,5 @@ pertController = ($scope) ->
       #console.log 'Loading: '+jdata
       return jdata
     else
-      r = new Pert(jdata).calculate()
-      #console.log 'Loading: '+r
-      return r
+      #console.log 'Loading: '+$scope.pbs
+      return $scope.pbs ?= new PBS(jdata).calculate()
diff --git a/src/controllers.coffee b/src/controllers.coffee
index fc988dd..f50b620 100644
--- a/src/controllers.coffee
+++ b/src/controllers.coffee
@@ -30,9 +30,11 @@ pertApp.controller 'pertDiagController', ($scope) ->
         edges:
           style: 'arrow'
       network = new vis.Network (document.getElementById 'pertDiagram'), { nodes: nodes, edges: connections }, options
-  $scope.$on 'dataChanged', ->
+  $scope.rebuild = ->
+    console.log 'rebuild'
     $scope.buildGraph $scope.fromLocalStorage()
-  $scope.buildGraph $scope.fromLocalStorage()
+  $scope.$on 'dataChanged', $scope.rebuild
+  $scope.rebuild()
 
 pertApp.controller 'ganttDiagController', ($scope) ->
   $scope.toDates = (list, startDay) ->
diff --git a/src/index.html b/src/index.html
index 8de9d61..47df66a 100644
--- a/src/index.html
+++ b/src/index.html
@@ -16,7 +16,7 @@
     <script src="angular-ui-router.js"></script>
     <script src="vis.min.js"></script>
     <script src="moment.js"></script>
-    <script src="pert.js"></script>
+    <script src="PBSlib.js"></script>
     <script src="app.js"></script>
     <script src="controllers.js"></script>
   </head>
diff --git a/src/pert.html b/src/pert.html
index 8cd95a8..be3b876 100644
--- a/src/pert.html
+++ b/src/pert.html
@@ -1 +1,4 @@
-<div id="pertDiagram" ng-controller="pertDiagController"></div>
+<div class="text-center" ng-controller="pertDiagController">
+  <button class="btn btn-primary" ng-click="rebuild()"><i class="fa fa-spinner"></i> Redraw</button>
+  <div id="pertDiagram" ></div>
+</div>
diff --git a/src/style.css b/src/style.css
index 1dcbacf..6068ed1 100644
--- a/src/style.css
+++ b/src/style.css
@@ -3,6 +3,7 @@
   width: 100%;
   border: 1px solid lightgray;
   margin-bottom: 1em;
+  margin-top: 1em;
 }
 
 .container {