git2063 sm:MDL-57292-master> git d
diff --git a/admin/tool/lpimportcsv/classes/framework_importer.php b/admin/tool/lpimportcsv/classes/framework_importer.php
index 796bd97..f0369f1 100644
--- a/admin/tool/lpimportcsv/classes/framework_importer.php
+++ b/admin/tool/lpimportcsv/classes/framework_importer.php
@@ -269,6 +269,14 @@ class framework_importer {
             $this->progress = $progress;
             $this->progress->start_progress('Theoretical max', count($this->flat));

+            // Map all parent idnumbers to the index they're stored in.
+            // This makes searching for children much more efficient.
+            $this->flatparents = array_map(function($key) {
+                if (property_exists($key, 'parentidnumber')) {
+                    return $key->parentidnumber;
+                }
+                return '';
+            }, $this->flat);
+
             // Build a tree from this flat list.
             $this->add_children($this->framework, '');
@@ -282,11 +291,13 @@ class framework_importer {
      * @param string $parentidnumber Add this competency to the parent with this idnumber.
      */
     public function add_children(& $node, $parentidnumber) {
-        foreach ($this->flat as $competency) {
-            if ($competency->parentidnumber == $parentidnumber) {
-                $node->children[] = $competency;
-                $this->add_children($competency, $competency->idnumber);
-            }
+        // The flat parents are stored as a mapping of index => parent value.
+        // We use the search feature of array_keys() to fetch all competencies within that parent.
+        $parents = array_keys($this->flatparents, $parentidnumber);
+        foreach ($parents as $flatindex) {
+            $competency = $this->flat[$flatindex];
+            $node->children[] = $competency;
+            $this->add_children($competency, $competency->idnumber);
         }
     }