diff --git a/views/ngXosViews/diagnostic/src/js/rackHelper.js b/views/ngXosViews/diagnostic/src/js/rackHelper.js
new file mode 100644
index 0000000..037ecdd
--- /dev/null
+++ b/views/ngXosViews/diagnostic/src/js/rackHelper.js
@@ -0,0 +1,85 @@
+(function () {
+  angular.module('xos.serviceTopology')
+  .service('RackHelper', function(serviceTopologyConfig, lodash){
+
+    this.getComputeNodeLabelSize = () => {
+      return serviceTopologyConfig.computeNode.labelHeight + (serviceTopologyConfig.instance.margin * 2)
+    }
+
+    /**
+    * Given a list of instance should get the Compute Node size.
+    * They are placed in rows of 2 with 5px margin on each side.
+    */
+   
+    this.getComputeNodeSize = lodash.memoize((instances) => {
+      const width = (serviceTopologyConfig.instance.margin * 3) + (serviceTopologyConfig.instance.width *2);
+
+      const rows = Math.round(instances.length / 2);
+
+      const labelSpace = this.getComputeNodeLabelSize();
+
+      const height = (serviceTopologyConfig.instance.height * rows) + (serviceTopologyConfig.instance.margin * (rows + 1)) + labelSpace;
+      return [width, height];
+    });
+
+    /**
+    * Give a list on Compute Node should calculate the Rack Size.
+    * Compute nodes are placed in a single column with 5px margin on each side.
+    */
+    this.getRackSize = (nodes) => {
+
+      let width = 0;
+      let height = serviceTopologyConfig.computeNode.margin;
+
+      lodash.forEach(nodes, (node) => {
+        let [instanceWidth, instanceHeight] = this.getComputeNodeSize(node.instances);
+
+        width = instanceWidth + (serviceTopologyConfig.computeNode.margin * 2);
+        height += (instanceHeight + serviceTopologyConfig.computeNode.margin);
+      });
+
+      return [width, height];
+    };
+
+    /**
+    * Given an instance index, return the coordinates
+    */
+   
+    this.getInstancePosition = (position) => {
+      const row = Math.floor(position / 2);
+      const column = (position % 2) ? 1 : 0;
+
+      // add ComputeNode label size
+      const labelSpace = this.getComputeNodeLabelSize();
+
+      // x = margin + (width * column) + ( maring * column)
+      const x = serviceTopologyConfig.instance.margin + (serviceTopologyConfig.instance.width * column) + (serviceTopologyConfig.instance.margin * column);
+
+      // y = label + margin + (height * row) + ( maring * row)
+      const y = labelSpace + serviceTopologyConfig.instance.margin + (serviceTopologyConfig.instance.height * row) + (serviceTopologyConfig.instance.margin * row);
+      return [x, y];
+    };
+
+    /**
+    * Given an Compute Node index, return the coordinates
+    */
+
+    this.getComputeNodePosition = (nodes, position) => {
+      const x = serviceTopologyConfig.computeNode.margin;
+
+      let previousElEight = lodash.reduce(nodes.slice(0, position), (val, node) => {
+        return val + this.getComputeNodeSize(node.instances)[1]
+      }, 0);
+
+      console.log('previousElEight ' + previousElEight);
+      const y =
+        serviceTopologyConfig.computeNode.margin
+        + (serviceTopologyConfig.computeNode.margin * position)
+        + previousElEight;
+
+
+      return [x, y];
+    };
+
+  });
+})();