diff --git a/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/api/model/Graph.kt b/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/api/model/Graph.kt
index 704567d..fc0e096 100644
--- a/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/api/model/Graph.kt
+++ b/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/api/model/Graph.kt
@@ -30,6 +30,34 @@ class Graph {
     fun findNode(label: String): Node? {
         return nodes.find { node -> node.label == label }
     }
+
+    // Only valid for di-graphs, otherwise much allow edges if incoming edges have a corresponding outgoing edge.
+    fun findSourceNodes(): HashSet<Node> {
+        val tempNodes = HashSet<Node>()
+        tempNodes.addAll(nodes)
+
+        edges.forEach { edge ->
+            val node = edge.sink
+            tempNodes.remove(node)
+        }
+
+        return tempNodes
+    }
+
+    fun firstNode(): Node {
+        return nodes.first()
+    }
+
+    fun findNodesConnectedFrom(node: Node): HashSet<Node> {
+        val tempNodes = HashSet<Node>()
+        edges.forEach { edge ->
+            if (edge.source == node) {
+                tempNodes.add(edge.sink)
+            }
+        }
+
+        return tempNodes
+    }
 }
 
 class Node(
diff --git a/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/impl/ReportRunner.kt b/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/impl/ReportRunner.kt
index 78eafd3..1e62973 100644
--- a/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/impl/ReportRunner.kt
+++ b/acropolis-report/src/main/kotlin/org/ephyra/acropolis/report/impl/ReportRunner.kt
@@ -1,12 +1,55 @@
 package org.ephyra.acropolis.report.impl
 
 import org.ephyra.acropolis.report.api.IReportRunner
+import org.ephyra.acropolis.report.api.model.Graph
 import org.ephyra.acropolis.report.api.model.GraphContainer
+import org.ephyra.acropolis.report.api.model.Node
 import org.springframework.stereotype.Component
 
 @Component
 private class ReportRunner : IReportRunner {
     override fun run(graphContainer: GraphContainer) {
         println("Running report")
+        buildNodeDepth(graphContainer.graph)
+
+        
+    }
+
+    fun buildNodeDepth(graph: Graph): HashMap<Node, Int> {
+        val startNode = pickStartNode(graph)
+
+        val depths = HashMap<Node, Int>()
+        depths[startNode] = 0
+
+        nodeDepth(startNode, graph, depths, 1)
+
+        return depths
+    }
+
+    fun nodeDepth(currentNode: Node, graph: Graph, depths: HashMap<Node, Int>, depth: Int) {
+        val connected = graph.findNodesConnectedFrom(currentNode)
+
+        // Remove all the nodes which are already numbered.
+        connected.removeAll(depths.keys)
+
+        // Number each of the connected nodes.
+        connected.forEach { con ->
+            depths[con] = depth
+        }
+
+        // Now apply the same process to each of the nodes we just numbered.
+        connected.forEach { con ->
+            nodeDepth(con, graph, depths, depth + 1)
+        }
+    }
+
+    fun pickStartNode(graph: Graph): Node {
+        val sourceNodes = graph.findSourceNodes()
+        return if (sourceNodes.isEmpty()) {
+            graph.firstNode()
+        }
+        else {
+            sourceNodes.first()
+        }
     }
 }