diff --git a/admin/tool/lp/classes/task/sync_plans_from_template_cohorts_task.php b/admin/tool/lp/classes/task/sync_plans_from_template_cohorts_task.php
index 39ccee5c1f0..358a4253f8f 100644
--- a/admin/tool/lp/classes/task/sync_plans_from_template_cohorts_task.php
+++ b/admin/tool/lp/classes/task/sync_plans_from_template_cohorts_task.php
@@ -52,7 +52,7 @@ class sync_plans_from_template_cohorts_task extends \core\task\scheduled_task {
      */
     public function execute() {
 
-        $missingplans = template_cohort::get_all_missing_plans();
+        $missingplans = template_cohort::get_all_missing_plans(self::get_last_run_time());
 
         foreach ($missingplans as $missingplan) {
             foreach ($missingplan['userids'] as $userid) {
diff --git a/admin/tool/lp/classes/template_cohort.php b/admin/tool/lp/classes/template_cohort.php
index dd4afe0ca45..1f529771307 100644
--- a/admin/tool/lp/classes/template_cohort.php
+++ b/admin/tool/lp/classes/template_cohort.php
@@ -180,28 +180,36 @@ class template_cohort extends persistent {
      * Note that only cohorts associated with visible templates are considered,
      * as well as only templates with a due date in the future, or no due date.
      *
+     * @param int $lastruntime  The last time the Cohort ssync task ran.
      * @param bool $unlinkedaremissing When true, unlinked plans are considered as missing.
      * @return array( array(
      *                   'template' => \tool_lp\template,
      *                   'userids' => array
      *              ))
      */
-    public static function get_all_missing_plans($unlinkedaremissing = false) {
+    public static function get_all_missing_plans($lastruntime = 0, $unlinkedaremissing = false) {
         global $DB;
 
-        $skipsql = !$unlinkedaremissing ? '(t.id = p.templateid OR t.id = p.origtemplateid)' : 't.id = p.templateid';
+        $planwhereclause = " WHERE (p.id is NULL AND (cm.timeadded >= :lastruntime1 OR tc.timecreated >= :lastruntime3 OR t.timemodified >= :lastruntime4))";
 
-        $sql = "SELECT cm.userid, t.*
+        if ($unlinkedaremissing) {
+            $planwhereclause .= " OR (p.origtemplateid IS NOT NULL AND cm.timeadded < :lastruntime2)";
+        }
+
+        $sql = "SELECT " . $DB->sql_concat('cm.userid', 'tc.templateid') . " as uniqueid, cm.userid, t.*
                   FROM {cohort_members} cm
                   JOIN {" . self::TABLE . "} tc ON cm.cohortid = tc.cohortid
                   JOIN {" . template::TABLE . "} t
                     ON (tc.templateid = t.id AND t.visible = 1)
-                   AND (t.duedate = 0 OR t.duedate > :time)
-             LEFT JOIN {" . plan::TABLE . "} p ON (cm.userid = p.userid AND $skipsql)
-                 WHERE p.id IS NULL
+                   AND (t.duedate = 0 OR t.duedate > :time1)
+             LEFT JOIN {" . plan::TABLE . "} p ON (cm.userid = p.userid AND (t.id = p.templateid OR t.id = p.origtemplateid))
+                  $planwhereclause
               ORDER BY t.id";
 
-        $results = $DB->get_records_sql($sql, array('time' => time()));
+        $params = array('time1' => time(), 'time2' => time(),
+                        'lastruntime1' => $lastruntime, 'lastruntime2' => $lastruntime,
+                        'lastruntime3' => $lastruntime, 'lastruntime4' => $lastruntime);
+        $results = $DB->get_records_sql($sql, $params);
 
         $missingplans = array();
         foreach ($results as $usertemplate) {
@@ -212,6 +220,7 @@ class template_cohort extends persistent {
                 $missingplans[$usertemplate->id]['userids'][] = $userid;
             } else {
                 unset($usertemplate->userid);
+                unset($usertemplate->uniqueid);
                 $template = new template(0, $usertemplate);
                 $missingplans[$template->get_id()]['template'] = $template;
                 $missingplans[$template->get_id()]['userids'][] = $userid;
diff --git a/admin/tool/lp/tests/task_test.php b/admin/tool/lp/tests/task_test.php
index 77083f52393..aee34644834 100644
--- a/admin/tool/lp/tests/task_test.php
+++ b/admin/tool/lp/tests/task_test.php
@@ -37,11 +37,20 @@ use tool_lp\plan;
 class tool_lp_task_testcase extends advanced_testcase {
 
     public function test_sync_plans_from_cohorts_task() {
+        global $DB;
+
         $this->resetAfterTest(true);
         $this->setAdminUser();
         $dg = $this->getDataGenerator();
         $lpg = $dg->get_plugin_generator('tool_lp');
 
+        // Sql to simulate the execution in time.
+        $cmsql = "UPDATE {cohort_members} SET timeadded = :currenttime WHERE cohortid = :cohortid AND userid = :userid";
+        $tplsql = "UPDATE {tool_lp_template} SET timemodified = :currenttime WHERE id = :templateid";
+        $plansql = "UPDATE {tool_lp_plan} SET timemodified = :currenttime WHERE id = :planid";
+
+        $currenttime = time();
+
         $user1 = $dg->create_user();
         $user2 = $dg->create_user();
         $user3 = $dg->create_user();
@@ -68,7 +77,9 @@ class tool_lp_task_testcase extends advanced_testcase {
         cohort_add_member($cohort->id, $user3->id);
         cohort_add_member($cohort->id, $user4->id);
 
+        $currenttime = $currenttime + 1;
         $task->execute();
+        $task->set_last_run_time($currenttime);
 
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
 
@@ -76,43 +87,73 @@ class tool_lp_task_testcase extends advanced_testcase {
         cohort_remove_member($cohort->id, $user3->id);
         cohort_remove_member($cohort->id, $user4->id);
 
+        $currenttime = $currenttime + 1;
         $task->execute();
+        $task->set_last_run_time($currenttime);
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
 
         // The template is now hidden, and I've added a user with a missing plan. Nothing should happen.
+        $currenttime = $currenttime + 1;
         $tpl->set_visible(false);
         $tpl->update();
+        $DB->execute($tplsql, array('currenttime' => $currenttime, 'templateid' => $tpl->get_id()));
+        $currenttime = $currenttime + 1;
         cohort_add_member($cohort->id, $user5->id);
+        $DB->execute($cmsql, array('currenttime' => $currenttime, 'cohortid' => $cohort->id, 'userid' => $user5->id));
         $this->assertFalse(plan::record_exists_select('userid = ? AND templateid = ?', array($user5->id, $tpl->get_id())));
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
+        $currenttime = $currenttime + 1;
         $task->execute();
+        $task->set_last_run_time($currenttime);
         $this->assertFalse(plan::record_exists_select('userid = ? AND templateid = ?', array($user5->id, $tpl->get_id())));
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
 
         // Now I set the template as visible again, the plan is created.
+        $currenttime = $currenttime + 1;
         $tpl->set_visible(true);
         $tpl->update();
+        $DB->execute($tplsql, array('currenttime' => $currenttime, 'templateid' => $tpl->get_id()));
+        $currenttime = $currenttime + 1;
         $task->execute();
+        $task->set_last_run_time($currenttime);
         $this->assertTrue(plan::record_exists_select('userid = ? AND templateid = ?', array($user5->id, $tpl->get_id())));
         $this->assertEquals(5, plan::count_records(array('templateid' => $tpl->get_id())));
 
         // Let's unlink the plan and run the task again, it should not be recreated.
+        $currenttime = $currenttime + 1;
         $plan = plan::get_record(array('userid' => $user5->id, 'templateid' => $tpl->get_id()));
         \tool_lp\api::unlink_plan_from_template($plan);
+        $DB->execute($plansql, array('currenttime' => $currenttime, 'planid' => $plan->get_id()));
         $this->assertTrue(plan::record_exists_select('userid = ?', array($user5->id)));
         $this->assertFalse(plan::record_exists_select('userid = ? AND templateid = ?', array($user5->id, $tpl->get_id())));
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
+        $currenttime = $currenttime + 1;
         $task->execute();
+        $task->set_last_run_time($currenttime);
         $this->assertTrue(plan::record_exists_select('userid = ?', array($user5->id)));
         $this->assertFalse(plan::record_exists_select('userid = ? AND templateid = ?', array($user5->id, $tpl->get_id())));
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
 
         // Adding users to cohort that already exist in plans.
+        $currenttime = $currenttime + 1;
         cohort_add_member($cohort->id, $user3->id);
         cohort_add_member($cohort->id, $user4->id);
+        $DB->execute($cmsql, array('currenttime' => $currenttime, 'cohortid' => $cohort->id, 'userid' => $user3->id));
+        $DB->execute($cmsql, array('currenttime' => $currenttime, 'cohortid' => $cohort->id, 'userid' => $user3->id));
 
+        $currenttime = $currenttime + 1;
         $task->execute();
+        $task->set_last_run_time($currenttime);
         $this->assertEquals(4, plan::count_records(array('templateid' => $tpl->get_id())));
+
+        // Test a user plan deleted will not be recreated
+        $currenttime = $currenttime + 1;
+        $plan = plan::get_record(array('userid' => $user4->id, 'templateid' => $tpl->get_id()));
+        \tool_lp\api::delete_plan($plan->get_id());
+        $currenttime = $currenttime + 1;
+        $task->execute();
+        $task->set_last_run_time($currenttime);
+        $this->assertEquals(3, plan::count_records(array('templateid' => $tpl->get_id())));
     }
 
     public function test_sync_plans_from_cohorts_with_templateduedate_task() {