diff --git a/lib/timeline/component/item/BackgroundItem.js b/lib/timeline/component/item/BackgroundItem.js
index a4ec1bd94..21cf92d69 100644
--- a/lib/timeline/component/item/BackgroundItem.js
+++ b/lib/timeline/component/item/BackgroundItem.js
@@ -1,4 +1,3 @@
-var Hammer = require('../../../module/hammer');
 var Item = require('./Item');
 var BackgroundGroup = require('../BackgroundGroup');
 var RangeItem = require('./RangeItem');
@@ -141,17 +140,14 @@ BackgroundItem.prototype.repositionX = RangeItem.prototype.repositionX;
  * Reposition the item vertically
  * @Override
  */
-BackgroundItem.prototype.repositionY = function(margin) {
+BackgroundItem.prototype.repositionY = function(margin) {  // eslint-disable-line no-unused-vars
   var height;
   var orientation = this.options.orientation.item;
 
   // special positioning for subgroups
   if (this.data.subgroup !== undefined) {
     // TODO: instead of calculating the top position of the subgroups here for every BackgroundItem, calculate the top of the subgroup once in Itemset
-
     var itemSubgroup = this.data.subgroup;
-    var subgroups = this.parent.subgroups;
-    var subgroupIndex = subgroups[itemSubgroup].index;
 
     this.dom.box.style.height = this.parent.subgroups[itemSubgroup].height + 'px';
 
diff --git a/lib/timeline/component/item/BoxItem.js b/lib/timeline/component/item/BoxItem.js
index aa2e1eea6..33a23eedc 100644
--- a/lib/timeline/component/item/BoxItem.js
+++ b/lib/timeline/component/item/BoxItem.js
@@ -1,5 +1,4 @@
 var Item = require('./Item');
-var util = require('../../../util');
 
 /**
  * @constructor BoxItem
diff --git a/lib/timeline/component/item/Item.js b/lib/timeline/component/item/Item.js
index cb16b7663..9dd4e055e 100644
--- a/lib/timeline/component/item/Item.js
+++ b/lib/timeline/component/item/Item.js
@@ -99,7 +99,7 @@ Item.prototype.setParent = function(parent) {
  * @returns {{start: Number, end: Number}} range with a timestamp for start and end
  * @returns {boolean} True if visible
  */
-Item.prototype.isVisible = function(range) {
+Item.prototype.isVisible = function(range) {  // eslint-disable-line no-unused-vars
   return false;
 };
 
@@ -244,9 +244,6 @@ Item.prototype._repaintOnItemUpdateTimeTooltip = function (anchor) {
                  this.data.editable !== false;
 
   if (this.selected && editable && !this.dom.onItemUpdateTimeTooltip) {
-    // create and show tooltip
-    var me = this;
-
     var onItemUpdateTimeTooltip = document.createElement('div');
 
     onItemUpdateTimeTooltip.className = 'vis-onUpdateTime-tooltip';
@@ -321,6 +318,7 @@ Item.prototype._repaintOnItemUpdateTimeTooltip = function (anchor) {
  */
 Item.prototype._updateContents = function (element) {
   var content;
+  var changed;
   var templateFunction;
   var itemVisibleFrameContent;
   var visibleFrameTemplateFunction; 
@@ -340,7 +338,7 @@ Item.prototype._updateContents = function (element) {
     if ((itemVisibleFrameContent instanceof Object) && !(itemVisibleFrameContent instanceof Element)) {
       visibleFrameTemplateFunction(itemData, itemVisibleFrameContentElement)
     } else {
-       var changed = this._contentToString(this.itemVisibleFrameContent) !== this._contentToString(itemVisibleFrameContent);
+       changed = this._contentToString(this.itemVisibleFrameContent) !== this._contentToString(itemVisibleFrameContent);
        if (changed) {
         // only replace the content when changed
         if (itemVisibleFrameContent instanceof Element) {
@@ -371,7 +369,7 @@ Item.prototype._updateContents = function (element) {
   if ((content instanceof Object) && !(content instanceof Element)) {
     templateFunction(itemData, element)
   } else {
-    var changed = this._contentToString(this.content) !== this._contentToString(content);
+    changed = this._contentToString(this.content) !== this._contentToString(content);
     if (changed) {
       // only replace the content when changed
       if (content instanceof Element) {
@@ -470,7 +468,7 @@ Item.prototype._updateEditStatus = function() {
     } else if(typeof this.options.editable === 'object') {
         this.editable = {};
         util.selectiveExtend(['updateTime', 'updateGroup', 'remove'], this.editable, this.options.editable);
-    };
+    }
   }
   // Item data overrides, except if options.editable.overrideItems is set.
   if (!this.options || !(this.options.editable) || (this.options.editable.overrideItems !== true)) {
diff --git a/lib/timeline/component/item/RangeItem.js b/lib/timeline/component/item/RangeItem.js
index 27dedd54e..485df4b57 100644
--- a/lib/timeline/component/item/RangeItem.js
+++ b/lib/timeline/component/item/RangeItem.js
@@ -1,4 +1,3 @@
-var Hammer = require('../../../module/hammer');
 var Item = require('./Item');
 
 /**